Assessment of risk management measures to...

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Assessment of risk management measures to reduce the exotic disease risk from the feeding of processed catering waste and certain other food waste to non-ruminants (Version 2.7) Project reference: SE4406 12th December 2014 A. Adkin, BSc, MSc, PhD1

D. C. Harris, BVSc, MRCVS2

S. Reaney, BSc.2

T. Dewé, BVSc(Hons), BAnimSc, MSc, MRCVS1

A. Hill, BSc, PhD1 H. Crooke, BSc, PhD3

T. Drew, MSc, PhD, MSB3

L. Kelly, BSc, PhD 1,4 1 Department of Epidemiology Science, Animal & Plant Health Agency, Woodham Lane, Weybridge, UK. Adkin, A [[email protected]], Hill, A [[email protected]], Dewé, T; 2 Operations Co-ordination Unit, Animal & Plant Health Agency, Worcester, UK. Harris, D [[email protected]], Reaney, S [[email protected]]; 3 Virology Department, Animal & Plant Health Agency, Woodham Lane, Weybridge, UK. Drew, T [[email protected]]; Crooke, H [[email protected]]; 4 Department of Mathematics and Statistics, University of Strathclyde, Glasgow. Kelly, L [[email protected]] Correspondence: Dr. Amie Adkin Senior Risk Analyst Department of Epidemiological Science Animal & Plant Health Agency Woodham Lane, Surrey KT15 3NB tel. 01932 357 892 fax. 01932 357 445 [[email protected]]

mailto:[email protected]




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Executive Summary

Under European Union (EU) Animal By-Product (ABP) legislation catering waste and certain foodstuffs no longer intended for human consumption and containing animal by-products are prohibited from being fed to livestock due to the potential risk of spreading exotic disease. Recent research commissioned by Defra, however, concluded that such food waste could be safely fed to livestock, if properly segregated, and if appropriate changes in legislation were made (e.g. former foodstuffs containing poultry-sourced ABP could be fed to pigs). It was noted further research was required to explore the feasiblility of putting in place control measures to ensure the additional risk of an outbreak of exotic notifiable disease from feeding processed catering/food waste to non-ruminants in Great Britain (GB) is no greater than negligible. In order to consider this issue a hazard identification, risk assessment, and evaluation of risk management measures was performed according to a modified OIE framework (OIE, 2012). A quantitative risk assessment was developed to estimate the probability of infection of an exotic notifiable disease in livestock and fish, given a theoretical system for processing food waste which included a heating step to 70°C, 100°C or 130°C. Overall results indicated that under each scenario investigated, assuming segregation and cross-contamination controls were as effective as current controls, the estimated mean risk was greater than negligible, (defined as more than one exotic disease infection every 1000 years). Results from two theorteical model systems for management of food waste were considered:

In considering the segregation of food waste by species (intra-species recycling and ruminant feed ban enforced) and a heating step of 100ºC or 130ºC, the highest risk of infection in GB from feeding industrially processed animal feed to pigs, poultry and farmed fish was estimated to be one infection of Foot and Mouth Disease (FMD) in pigs every 74 years (equivalent to a low risk).

When considering the use of processed food waste without segregation, even at the highest temperatures, the estimated risk of infection increases, ranging from negligible risk for most of the hazards considered to one infection every two years for African Swine Fever (ASF) in pigs.

Key to reducing the risk posed by feeding processed food waste to pigs, poultry and farmed fish is maintaining a very low cross-contamination rate of the final product with raw input materials and stringent segregation of materials from all input source materials. The results include considerable uncertainty due to a lack of clarity about the effectiveness of potential industrial controls, and a lack of data for key inputs such as the total amount of contaminated products entering GB per year via different pathways and the titre of infectivity in those contaminated products. The risk assessment could be updated upon the availability of key scientific information potentially reducing the uncertainty in the model estimates. The risk assessment does not consider illegal use of food waste in animal feed within the assessed risk. The illegal feeding of livestock and fish with non-permitted food waste has been identified as an important route of incursions of exotic livestock disease, as evidenced by the 2001 outbreak of FMD in the UK. The likelihood of intentional, illegal swill feeding may increase if industrial processing of food waste is permitted, and additional safeguards to those considered here may be required to mitigate this risk.

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Hazard Identification and Risk Assessment summary The final risk estimates of the risk assessment were provided for two model systems:

Model System 1: Intra-species recycling ban was enforced, with no ruminant origin food material sourced. The risk estimate was provided for those sourcing streams where it was deemed that food waste could be sufficiently segregated by species (commercial catering waste and former foods).

Model System 2: Intra-species recycling ban not operating, all animal origin food material was sourced. The risk estimate was provided including any source stream (all catering waste and former foods) where it was deemed that feed could be produced to adhere only to separation of feeds during processing and on farm.

A hazard identification was conducted which identified 16 different pathogens including bacteria, prions and viruses that may be present in GB food waste not currently permitted for feeding to non-ruminants and fish. The release assessment investigated the amount of infected animal products entering food waste from three different sources of food waste:

Catering waste from all species originating from domestic kitchens.

Catering waste originating from restaurants, canteens, fast food premises.

Foodstuffs no longer intended for human consumption originating from manufacturing and retail premises.

The entry of exotic pathogens into the GB food waste supply from three different routes considered most likely for entry of the hazards were investigated – 1. illegal import, 2. legal import, and 3. domestic production of meat, meat products, fish, dairy, eggs and live animals. Key assumptions and available data were used to estimate a mean total of 38.6 kg of infected meat (90% percentiles 3, 120), 22.4 kg of infected fish (90% percentiles 2, 70), 28.5 kg of infected dairy products (90% percentiles 2, 88), and 1 kg of infected eggs and egg products (90% percentiles 0.07, 3) entering collected GB food waste (catering and former food waste) per year. It was assumed that this infected material was homogenously mixed with all waste food materials produced annually. The concentration of oral infectivity in the food waste (dose/kg) for each processing temperature was assumed to be dependent on the initial amount of infectivity in the infected product, probability of pathogen survival post handling, reduction in infectivity due to processing, the total weight of food waste collected and the conversion of infectivity into oral dose units. A review of the literature identified that many of these parameters are uncertain, particularly the average initial amount of infectivity and the amount of infectivity required to initiate infection via the oral route. This was also highly variable between exotic diseases. Highly pathogenic – porcine epidemic diarrhea (HP-PED), highly pathogenic avian influenza (HP-AI), foot and mouth disease (FMD), and infectious pancreatic necrosis (IPN) require relatively low infectious oral doses to initiate infection demonstrating the importance of preventing cross-contamination in the supply chain for these diseases. Further, the difference between the Oral ID50 value and the minimum infectious dose (3.5 logs) for highly pathogenic - porcine reproductive and respiratory syndrome (HP-PRRS) illustrates the variability between animals which may depend on pathogen strain, species, breed and the state of health or age of the animal concerned.

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The exposure assessment evaluated the pathways necessary for exposure of animals to the hazards identified in food waste and provided an estimate of the number of 'loads' fed to animals each year and the oral dose per load. A ‘load’ was defined as the amount of processed food waste an animal would be fed daily. It was assumed that the current safeguards in operation for the mass processing of food waste by anaerobic digestion, composting, and rendering/ incineration would limit the amount of raw food to that which livestock, fish and wildlife are currently exposed. The potential risks associated with the production and feeding of currently banned waste food to livestock will be highly dependent on the specific method of (legal) production, distribution and the effectiveness of risk management measures that are put in place. For Model system 1, it is assumed that there is a low probability (rare but may occur) of a breach event resulting in contamination between segregated feeds (failure of the intra-species recycling ban). This is based on the current implementation model of segregation for bakery products and restricted proteins. For Model system 1 and 2, it was estimated that there was a very low (very rare but cannot be excluded) probability of cross contamination of raw waste food materials and the cooked product. For both systems, the probability of receiving an infective dose via correct processing and segregation of feed, and via accidental failure to segregate and of contamination of processed feed with raw material was compared. In the consequence assessment, an oral dose response was applied and the final risk estimate, the probability of infection per year, for each of the 16 hazards was estimated. Assuming a steady state within the system, the number of years between an exotic disease outbreak was also estimated. The results for Model system 1 (where food was segregated by species - intra-species recycling and ruminant feed ban are enforced) indicated that for the majority of pathogens, the estimated risk of infection in GB as a result of feeding industrially processed animal feed to pigs, poultry and farmed fish was negligible (so rare that it does not merit to be considered). However, as a result of persistence of the pathogen during heat processing and/or the accidential contamination of cooked feed with raw product through by-pass, certain hazards were assessed as non-negligible. The exceptions at the lowest temperature of 70ºC were an estimated

medium risk (occurs regularly) for an infection of infectious pancreatic necrosis IPN (in fish),

low risk (rare, but does occur) of infection of FMD in pigs and Newcastle Disease (ND) in poultry,

very low risk (very rare but cannot be excluded) of infection of HP-AI in poultry and ASF in pigs.

When increasing the heat processing step to 100°C and 130°C, ASF, IPN, FMD and ND remain as a non-negligible probability of causing infection, due to contamination of cooked feed with raw product. The highest estimated risk across all 16 hazards at the higher processing temperatures of 100ºC and 130ºC, was an infection once in 74 years for FMD in pigs. The results for Model system 2 (where food is not segregated by species with no feeding permitted to ruminants - ruminant feed ban only is enforced) indicate that the risk of exotic

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disease infection increases substantially. With no segregation, Brucella, S Gallinarum, Chronic wasting disease (CWD), Aujeszky's disease (AD), Enzootic bovine leucosis (EBL), Sheep pox and goat pox (SPP, GTP) and Swine vesicular disease (SVD) posed an estimated negligible risk at any processing condition. A low to very low risk of infection was estimated for Anthrax spores, HP-PRRS, HP-PED, IPN, Classical swine fever (CSF) and FMD given certain processing conditions. The greatest risk of infection was deemed to be from ASF, HP-AI and ND, with a medium risk of infection even at higher temperatures. Of the latter, ASF was estimated to pose the greatest risk with an estimated infection once every two years. There was a large degree of uncertainty associated with the results for HP-AI and ASF due to the uncertain average titre (measured in logs) of the virus expected in the relevant meat and egg products. A more precise estimate of the average titre expected in these commodities from infected livestock would reduce the uncertainty associated with the main output for these hazards.

The risk estimates presented were dependent on several key assumptions:

Due to the time available, and number of potential hazards and product types, via different import pathways, it was necessary to simplify the risk assessment. In particular, it was assumed that the weight of infected products entering GB was the same as that previously estimated for CSF in illegally imported meat products (Hartnett et al., 2004) with a mean value of 263 kg per year. For the majority of pathogens this is most likely an overestimate, However, for certain hazards and product types the range used may not include the true value; this is unknown given the absence of information to provide an indication of the plausible ranges and true value. Updated research in this area would be beneficial as this estimate was identified as highly influential on the final model results. However, if such data was collected, it may only be valid for a few years as the global exotic disease situation varies over time.

There are limited information on the true weight of infected products entering GB via the legal importation pathway and those domestically infected (via another route) entering the food chain. It was assumed that the ratio of illegally imported infected meat to legally imported infected meat and domestically infected meat was 100:10:1.

It was assumed there was no minimum threshold dose to initiate infection, with each infectious particle’s action assumed as independent, and with any infectivity in food waste assumed to be homogenously spread. Therefore, 1000 feed servings with a specified level of infectivity has the same impact (i.e. potential to cause infection) as 10,000 feed servings with ten-fold less organisms.

It was assumed that the required minimum temperature was held for the required time throughout the food mass.

It was assumed that the same level of care is taken to prevent wildlife or livestock access to food waste during collection, storage and processing as for the current disposal systems in place (for example, anaerobic digestion, rendering, landfill). In other words, no additional risk from the proposed collection, storage and processing of the theoretical food waste system is considered.

In the absence of data on the specific dry weight, nutritional value of the proposed food waste, and the manufacturing process associated with animal feed in either a

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liquid or dried product, it was assumed that the weight of food waste equalled the weight of feed consumed per day.

There is considerable uncertainty associated with scale of the theoretical industry processing the animal feed and therefore the proportion of feed manufactured for each target livestock sector. These parameters significantly affect the risk estimates produced from the risk assessment.

Data gaps were identified for specific pathogens. For example,

o Little quantitative information could be found on the initial infectivity in

products for Brucella, S. Gallinarum, EBL, SPP and GTP. This may reflect the fact that very low levels are present.

o There were little data on the oral dose associated with CWD and EBL. Conservative estimates were used for CWD using data from another prion disease – BSE. However, the assumptions that the diseases have similar oral doses may be incorrect. Given the use of assumptions for the initial loadings and oral dose for EBL and CWD, the results for these pathogens may not be reliable.

Within the assessment, parameters are represented using a distribution (range) to capture the uncertainty associated with the parameter. A sensitivity analysis was conducted to estimate the impact of each of these ranges on the final output. The results of the sensitivity analysis were relatively similar across three selected example pathogens (FMD, IPN and anthrax spores). There were several uncertain parameters distributions strongly associated with the final outputs: (1) infectivity titre in product (ID50/kg), (2) the amount of infected illegally imported meat (kg), (3) the percentage of commercial waste to animal feed manufacture (%), (4) oral dose (Oral ID50/ID50), and (5) the probability pathogen survival post handling in food (%). For input parameters 1, 2, 4 and 5 further data could be commissioned to reduce the uncertainty. However, for parameter 3, it is difficult to accurately estimate the percentage of commercial food waste manufactured to legal animal feed in the absence of a process in place. For the baseline model 1, it was assumed that the parameter was equal to the upper proportion of pigs historically fed swill, 2.4% of standing pig population. In a scenario, approximately 10% of the standing population was fed the processed food waste. The highest risk estimate increased to one infection of FMD in pigs once every 22 years. Other scenarios were also conducted to investigate the influence on the results of further uncertain parameter values. For example, doubling the amount of infected products per year, or doubling the probability of cross-contamination of processed feed with raw food waste, increased the estimated risk of infection for FMD in pigs from one infection in 74 years to one infection in 40 years. In summary, when considering the segregation of waste food assuming the same effectiveness as currently implemented for segregation for other materials, there would be a negligible risk (so rare that it does not merit to be considered) for the majority of hazards. The greatest risk of infection is low for FMD in pigs (one infection every 74 years) when for processing food waste to 100ºC to 130ºC. When considering the use of processed food waste without segregation, the estimated risk of infection increases, ranging from negligible risk for many of the hazards to Qualitative rank (one infection every two years) for ASF, even at the highest processing temperatures. Key to reducing the risk posed from feeding

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processed food waste to pigs, poultry and farmed fish is maintaining a very low cross-contamination rate of the final product with raw input materials and the correct and stringent segregation of materials from all input source materials as per the current standards achieved with bakery waste and restricted proteins enforced by sampling and inspections.

Risk management summary The two model systems investigated in the risk assessment, Model System 1 and 2, were considered within the risk management section. Two end-products have also been considered, a dry coarse meal and a liquid / semi solid product. No consideration has been given to the detection of heavy metals, mycotoxins or other biological or chemical hazards, which may render incoming material from waste streams as unsafe. The economic viability of either system in today’s economic climate is also not considered, in particular the competition for food waste as a starting material for anaerobic digestion plants and for use in pet food. It was concluded that there is insufficient control in domestic kitchens to enable this waste stream to enter Model system 1. However catering waste from commercial kitchens and food no longer intended for human consumption from food manufacturers and retail shops could enter such a system given a clear list of eligible and ineligible products for reference. In addition, operators would need to take responsibility for ensuring adequate separation at supplying food businesses and in their sourcing by feed business operators i.e. the processing plants. The requirements for Model system 1 have been considered against the background of existing legislative arrangements and systems operating to collect and use bakery products containing milk, eggs, non-ruminant gelatine from supermarket returns depots and those operating to separate fishmeal from ruminant feed and ruminant access. The operation of controls in ABP processing plants were also considered, when assessing requirements to prevent contamination of processed product with raw product. In addition, the swill feeding controls existing before the ban in 2001 were considered when assessing the potential location of the processing plant. Key control measures required to operate a successful system include:

Safe sourcing of raw materials,

Controls during transport,

Responsible management and audit of supply,

Location of the processing plant, (not on the same site as farm animals),

A ‘checking point’ for ensuring food material from only the intended target species enters the system pre-processing (a ‘picking line’),

Strict separation of material from material originating from non-target species throughout all processing and post processing steps,

Robust processing,

Prevention of accidental contamination of raw material into finished product and control of fomites,

And negative release to PCR analysis; test to ensure that adequate separation of material originating from target and non-target species has been maintained throughout the system from source to finished product.

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Currently foodstuffs containing animal proteins are grouped into lists of products eligible for feeding to farm animals, eligible for landfill, and those that require disposal as per the requirements for Category 3 ABPs. It is envisaged that by using similar lists and adopting safe sourcing principles it would be possible to apply segregation measures in both food manufacturing/ retailing businesses and in catering businesses, restaurants, canteens and fast food outlets. Thoroughly auditing segregation measures at supplying food businesses and the successful operation of a picking line on entry of food waste into the processing plant are key control measures to preclude ineligible products from being used. Selection of product eligibility is partly driven by the effectiveness of identifying certain product types on the picking line. For example, products including sauces would need to be omitted due to the masking effect on visually identifying meat products. Of course, if the product was from a single species source i.e. a factory only handling a single species product, or products in identifiable packaging/ wrappers, it could be considered on a case by case basis for inclusion by the processing plant operator. The processing plant operator would be ultimately responsible for the safe sourcing of raw material. Sampling of the final product and testing by PCR provides an indication of the effectiveness of segregation in the supply chain and is a critical control point on entry into the processing plant. Motivation to ensure effective controls are established is likely to be higher in the feed industry than in the food industry, where surplus foodstuffs are often considered a waste, rather than a potential feed for animals. Systems currently in use have proved that if the receiving feed businesses (processors & businesses handling and using processed product further down the chain) are motivated to deliver protocols that identify separation inadequacies to a high standard, these systems can be effective. However, if feed operators do not understand the significance of the controls and are prepared to take-short cuts to save money or operate sub-standard protocols, then control systems can fail, with potentially widespread financial and animal health and welfare implications. The major advantage of Model system 2 is the sourcing of material, which can enter the system from any of the three waste streams, without the requirement for separation at source. There would still be an onus on supplying food businesses and receiving feed businesses (processor) to ensure only safe material enters the system. However, providing these requirements are met, then all food waste could be used. There would also be no need to test the finished product post-processing for speciation of proteins. This model system would enable a more extensive and local supply network compared to model system 1 and to a large extent minimises the increased risks inherent in complex requirements for species separation in the supply chain. The advantages and disadvantages of allowing a liquid or a dry final product are discussed. A dry final product provides increased opportunities for use and distribution in the feed chain. However, it also increases the number of points at which separation failure may occur, with an increasingly complex distribution chain through which to trace product and a larger potential number of exposed animals, if significant breaches occur. A liquid final product limits the use and distribution opportunities available and may increase the likelihood for smaller scale operators to be involved. It has potential disadvantages associated with the former swill feeding operations in terms of odour and form of final product and the potential for increased welfare issues in pig populations.

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Contents

1. INTRODUCTION......................................................................................................................... 11

2. METHODOLOGY ....................................................................................................................... 12

3. SCOPE OF THE WORK ............................................................................................................ 13

3.1 IDENTIFICATION OF SOURCE MATERIALS STREAMS AND PRODUCT TYPES ................................... 14 3.2 INTRA-SPECIES RECYCLING AND RUMINANT FEED BAN ................................................................. 15 3.3 PROCESSING STANDARDS FOR PRODUCING ANIMAL FEED FROM FOOD WASTE ........................... 15

4. HAZARD IDENTIFICATION ...................................................................................................... 18

5. MODEL OVERVIEW .................................................................................................................. 20

6. RELEASE ASSESSMENT FOR FOOD WASTE ..................................................................... 22

6.1 AMOUNT OF INFECTED PRODUCTS ENTERING BRITISH WASTE FOOD PER YEAR (KG) .................. 23 6.1.1 Estimated amount of illegally imported contaminated products entering GB

per year (kg) ........................................................................................................................ 23 6.1.2 Estimated amount of legally imported contaminated products entering GB per

year (kg) ............................................................................................................................... 24 6.1.3 Estimated amount of domestically produced contaminated products per year

(kg) ........................................................................................................................................ 25 6.1.4 Estimated probability of contaminated products entering waste food (%) ....... 25

6.2 CONCENTRATION OF ORAL INFECTIVITY IN FOOD WASTE BY TEMPERATURE PROCESSED (ORAL

ID50/KG) .......................................................................................................................................... 26 6.2.1 Initial loading of infectivity in product type (ID50/kg) ............................................... 27 6.2.2 Probability of pathogen survival post handling (%) ................................................. 28 6.2.3 Conversion of ID50 units into oral doses (oral ID50/ID50) .......................................... 29 6.2.4 Total weight of food waste collected per year (kg) .................................................. 30 6.2.5 Reduction in infectivity from processing of food waste into feed (%) ................ 31

7. EXPOSURE ASSESSMENT TO ANIMAL FEED .................................................................... 32

7.1 ROUTES OF EXPOSURE OF ANIMALS TO PROCESSED ANIMAL FEED ............................................. 36 7.2 NUMBER OF SPECIES SPECIFIC LOADS PROCESSED INTO ANIMAL FEED FROM FOOD WASTE

(LOADS PER YEAR) ......................................................................................................................... 38 7.2.1 Proportion of food waste being diverted to animal feed (%) ................................. 38 7.2.2 Proportion of feed manufactured into different livestock sectors (%) ................ 39 7.2.3 Amount of processed waste consumed by livestock species per day

(kg/animal/day) .................................................................................................................. 41 7.3 DOSE CONSUMED PER LOAD (ORAL ID50) ..................................................................................... 41 7.4 PROBABILITY OF EXPOSURE GIVEN SEGREGATION, SEGREGATION FAILURE AND CROSS

CONTAMINATION OF COOKED MATERIALS WITH RAW FOOD .......................................................... 42 7.4.1 Probability of a segregation failure (%) ....................................................................... 44 7.4.2 Probability of cross contamination of cooked materials with raw food waste (%)

............................................................................................................................................... 44

8. CONSEQUENCE OF EXPOSURE TO ORAL DOSE .............................................................. 45

8.1 PROBABILITY OF INFECTION PER LOAD.......................................................................................... 45 8.2 PROBABILITY OF INFECTION PER YEAR BY EXPOSURE ROUTE ...................................................... 45

9. RESULTS .................................................................................................................................... 49

9.1 ESTIMATED WEIGHT OF INFECTED MATERIAL ENTERING FOOD WASTE ......................................... 50 9.2 RESULTS FROM IMPLEMENTATION OF AN INTRA-SPECIES BARRIER ............................................. 50 9.3 RESULTS FROM NON-SEGREGATION OF FOOD WASTE .................................................................. 52

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9.3 KEY ASSUMPTIONS ......................................................................................................................... 54 9.4 SENSITIVITY ANALYSIS AND SCENARIOS ........................................................................................ 55

9.4.1 Sensitivity analysis ........................................................................................................... 56 9.4.2 Scenario 1: Amount of infected products entering British food waste per year

(kg) ........................................................................................................................................ 57 9.4.3 Scenario 2: Percentage of commercial waste food processed into feed

increased ............................................................................................................................. 58 9.4.4 Scenario 3: Reduction in exposure due to species segregation of food waste

(IPN) ...................................................................................................................................... 59 9.4.5 Scenario 4: Probability of cross contamination of cooked materials with raw

food waste (%) ................................................................................................................... 59 9.5 COMPARISON OF RESULTS TO OTHER RISK ASSESSMENTS .......................................................... 60 9.6 MAIN CONCLUSIONS FROM THE RISK ASSESSMENT ...................................................................... 61

10. RISK MANAGEMENT ................................................................................................................ 63

10.1 MEASURES TO REDUCE THE RISK OF CROSS CONTAMINATION OR BY-PASS ............................ 63 10.2 MODEL SYSTEM 1 – INTRASPECIES RECYCLING BAN IS IN PLACE, NO RUMINANT ORIGIN

MATERIAL CAN BE SOURCED ...................................................................................................... 63 10.3 RISK MANAGEMENT CONTROLS AND CRITICAL CONTROL POINTS ............................................ 68 10.4 MODEL SYSTEM 2 – INTRASPECIES RECYCLING BAN IS NOT IN PLACE, ALL ANIMAL ORIGIN

MATERIAL CAN BE SOURCED ...................................................................................................... 70 10.5 FINAL PRODUCT POST PROCESSING .......................................................................................... 71 10.6 RISK MANAGEMENT CONCLUSIONS ........................................................................................... 72

11. REFERENCES ............................................................................................................................ 74

12. APPENDIX 1: HAZARD IDENTIFICATION ............................................................................. 90

13. APPENDIX 2: INITIAL LOADING OF PATHOGEN IN PRODUCT TYPE ........................... 104

14. APPENDIX 3: CONVERSION OF ID50 UNITS INTO ORAL DOSES ................................... 109

15. APPENDIX 4: THERMOSTABILITY OF PATHOGENS IN PRODUCT BY PROCESSING

CRITERIA .................................................................................................................................. 114

16. APPENDIX 5: ASSESSING THE PROBABILITY OF CROSS CONTAMINATION

BETWEEN SEGREGATED FEEDS ....................................................................................... 120

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1. INTRODUCTION

The feeding of waste food to domestic pigs is a practice regulated and carried out in many countries including the USA, New Zealand, and South Korea. However, there are a number of routes by which exotic notifiable pathogens may enter the country and contaminate materials entering food waste. The feeding of contaminated materials to animals can spread diseases such as Foot and Mouth Disease (FMD) and Classical Swine Fever (CSF). The FMD epidemic of 2001 in the United Kingdom (UK) was caused by the feeding of uncooked catering waste containing virus to pigs, and prior to 2001, excluding the airborne outbreakof the early eighties, the last epidemic of FMD occurred in 1967-68 when over 400,000 livestock were slaughtered. The origin of this incursion was linked to pigs fed bones from frozen lamb carcasses legally imported from Argentina (MAFF, 1968).

Before the 2001 FMD outbreak, the production and feeding of processed food/catering

waste to pigs was controlled by the Animal By-Products Order 1999. Under this Order

licensed operators were permitted to (i) process catering waste and (ii) render non-

mammalian waste for feeding to pigs. The order also required a license for those farmers

who purchased and transferred swill from the site of the licensed processors to feed their

pigs. In 2001, 74 premises in the UK were licensed to process swill and 93 (including all the

74 licensed processors) were licensed to use it for feed (Parliamentary and Health Service

Ombudsman, 2007). It was an offence under the Order to bring unprocessed catering waste

onto any premises where ruminant animals, pigs or poultry were kept, and premises had to

be inspected four times a year, although approved processing plants could be co-located, as

a separate premises, on the same site.

During the 2001 FMD outbreak, on the 24th May 2001, the UK prohibited the feeding of all catering waste to livestock with the Animal By-Products (Amendment) (England) Order 2001. In addition, there was a ban on feeding any livestock catering waste imported into Great Britain (GB) or any feeding stuffs that may have been in contact with food waste. This was followed by the subsequent enactment at the European level of the EU Animal By-Products (ABP) legislation (EC 1774/2002 replaced by Regulation (EC) 1069/2009 & Regulation (EC) No.142/2011).

However, waste food is potentially of high nutritional value as an animal feed. Defra has previously commissioned research on the recycling of catering and food waste (FO0218) to obtain information for sustainable and safe use of food and catering waste (July 2013). Key findings of the research included that more food waste could be used as animal feed, if properly segregated and if appropriate changes in legislation were made (e.g. former foodstuffs containing poultry-sourced ABP could be fed to pigs), and a more systematic assessment would be needed to determine risks to human and animal health from the recycling of food and catering waste through livestock production.

In order to address the gaps in the evidence base to inform development of animal by-product policy, Defra requested research be conducted to explore whether it would be feasible to put in place control measures to ensure that the additional risk of an outbreak of exotic notifiable animal disease, that might arise from the feeding of processed catering and certain other food waste to non-ruminants, is no greater than negligible, and to inform what those control measures are.

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2. METHODOLOGY The purpose of the risk analysis was to assess the risk posed to livestock and fish from exotic disease present in food waste containing products of animal origin, which are currently ineligible for feeding to farm animals, if it was processed at an industrial scale and fed to pigs, poultry and farmed fish. In addition, the risk management measures required to mitigate this risk to a negligible probability and enable certain controls under the Transmissible Spongiform Encephalopathies (TSE) and ABP legislation relating to feed controls to be complied with were determined. In order to fulfil this purpose a hazard identification, risk assessment, and evaluation of risk management measures has been performed according to a modified OIE framework (OIE, 2004). According to the OIE framework, the four components of risk assessment are release assessment, exposure assessment, consequence assessment and risk estimation. Hazard identification is the process of identifying the pathogens capable of transmitting disease which are associated with the commodity of concern (OIE, 2004). The release assessment in this report determines the likelihood of entry of exotic disease and describes and quantifies the biological pathways necessary for that hazard to be introduced into waste food. In the time available, three of the routes deemed to be the most likely for entry of the hazards identified were investigated – the illegal import, legal import, and domestic production of meat, meat products, fish, dairy, eggs and live animals. The exposure assessment consists of describing the pathways necessary for exposure of animals to the hazards identified through feed processing. The consequence assessment evaluates the relationship between exposures to a hazard, the consequences of those exposures and their likelihood.The risk estimation integrates the above findings to produce summary measures of the risks associated with the identified hazards (OIE, 2004). The risk management section describes the measures required to achieve the level of acceptable risk. The risk assessment is stochastic, implemented in Microsoft Excel (2010 Version) with the add on package, @Risk (version 6.1) to estimate the annual probability of infection by animal pathogen. The risk assessment uses distributions to descibe any known uncertainty associated with the input parameters. However, it should be noted that as the risk assessment concerns a theoretical industrial process, with little information regarding scale and livestock sectors participation, there is considerable uncertainty associated with model outputs not included in the numerical calculation. The risk assessment presented, therefore, represents the most reasonable case scenario currently available at this time, and could be updated if new evidence emerges. The final risk estimate of the annual probability of infection by animal pathogen is presented qualitatively where the following definitions are used:

Probability term (EFSA,

2006)

Probability of event per year (EFSA, 2006; OIE, 2004)

If assumed stable (event once every)

Negligible So rare that it does not merit to be considered

<0.1% > 1000 years

Very low Very rare but cannot be excluded

0.1% to 1% 100 to 1000 years

Low Rare, but does occur 1% to 10% 10 to 100 years Medium Occurs regularly 10% to 66% 1.5 to 10 years High Occurs very often 66% to 90% 1.1 to 1.5 years Very high Events occur almost certainly >90% < 1.1 years

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3. SCOPE OF THE WORK

In consultation with Defra, the risk question was defined: The feeding of farmed animals with feed containing catering waste and certain former foodstuffs is currently prohibited. If such material was fed to pigs, poultry and farmed fish what risk management measures (including segregation, transportation and processing) would be required to reduce the likelihood of an exotic disease outbreak in pigs, poultry, farmed fish and non-target species, i.e. cattle, sheep, goats, camelids, and farmed deer, to a negligible level? A number of key assumptions frame the risk analysis:

The risk question is based on a theoretical industrial scale processing of animal feed.

The risk assessment assumes a constant level of infectivity in GB food waste arising from contaminated illegally imported products, legally imported products and domestically produced animals infection via other pathways.The level estimated will vary by pathogen, and in the absence of further information is assumed to the maximum previously assessed for Classical Swine Fever (Hartnett et al., 2004).

The risk assessment assumes homogenous mixing of infected products within the food waste with a dose response model that does not assume a minimum threshold dose to intiate infection in animals.

The risk assessment does not include the risks associated with backyard feeding of livestock or the illegal use of food waste in animal feed. The illegal feeding of livestock and fish non-permitted food waste is an important route of incursions of exotic disease in livestock, as evidenced by the 2001 outbreak of Foot and Mouth Disease in the UK. The probability of intentional, illegal swill feeding may increase if industrial processing of food waste is permitted, and therefore additional safeguards may be required.

Although other techniques may be applied, only heat treatment within an industrial sized plant was considered as a processing method.

Although the intended recipients of the derived animal feed are pigs, poultry, and farmed fish, the risk associated with potential mixing with ruminant feed or access by ruminants and other non-target livestock species has been evaluated. Therefore, exotic disease pathogens specifically pathogenic to cattle, sheep, goats, camelids, and farmed deer, were included in the hazard identification in addition to those that are pathogenic to swine, poultry and fish. Of the notifiable diseases listed by the World Organisation for Animal Health (OIE), those that are not associated with livestock (i.e. affecting lagomorphs (hares, rabbits), shellfish and bees) were excluded. Animal diseases already present in Britain, human diseases, toxins and other chemicals, parasites, and antibiotic resistant pathogen strains were excluded from the scope of the risk assessment. For farmed fish, a number of exotic pathogens are of concern. However, as they share similar sensitivities to heat, a single (endemic) pathogen was included in the hazard identification: Infectious Pancreatic Necrosis virus. This virus demonstrates high

14

thermal resistance and therefore acts as the benchmark, or worst-case scenario, for fish pathogens undergoing heat treatment.

3.1 Identification of source materials streams and product types

Catering waste is a Category 3 ABP and is defined as all food waste “originating in restaurants, catering facilities and kitchens, including central kitchens and household kitchens”. Therefore, such waste may include uneaten dairy products, raw and cooked eggs or egg shells, raw and cooked meats, chicken carcase materials, bones of sheep and cattle, offal and fats, but not those materials defined as Category 1 or 2 materials. Category 1 and 2 materials include the brain, spinal cord, and intestines of cattle and sheep, manure and intestinal contents which are removed at abattoir. Raw liquid milk can be sold direct to consumers by farmers or through farmers markets in England, Wales and N.Ireland (not in Scotland), so it was assumed it can enter catering waste streams from domestic kitchens, but not catering waste streams from commercial kitchens or waste streams from food manufacturing or retail establishments. Foodstuffs, containing products of animal origin, which are not currently eligible for feeding to farm animals are defined as foodstuffs associated/containing products of animal origin, other than catering waste, such as meat, offal, fish and shellfish, which are no longer intended for human consumption for commercial reasons or due to problems of manufacturing or packaging defects, or other defects which do not present any risk to humans or animals. This does not include foodstuffs no longer intended for human consumption, such as bakery and confectionary products containing products of animal origin, such as milk, eggs, fats and non-rumiunant gelatine, which can currently be fed to farm livestock without further processing, or fats, processed milk and processed egg products, which can be fed to farm animals in accordance with current ABP Regulations. There is a complicated legislative position on raw milk, where milk/ milk products treated to ABP processing requirements can be marketed for general sale, whereas other unprocessed milk/ milk products can be sent under national rules directly from registered milk processing establishments to registered farms. This also applies to milk from retail/ manufacturing premises, which doesn’t satisfy ABP processing standards. Pasteurised milk/ milk products and dairy products manufactured from pasteurised milk do not satisfy ABP processing requirements. Pasteurised milk/ milk products can enter catering waste streams from domestic kitchens, commercial kitchens and waste streams from food manufacturing and retail premises. Dairy products, such as cheese made from unpasteurised (raw) milk are more widely available and could enter all of the same waste streams. In summary, there are three sourcing scenarios under consideration:

Catering waste from all species originating from domestic kitchens.

Catering waste originating from restaurants, canteens, fast food premises.

Foodstuffs no longer intended for human consumption originating from manufacturing and retail premises.

Within these sourcing streams, the risk analysis considered the risk associated with the following animal, fish and dairy products not currently permitted into animal feed:

15

Meat and meat products1 (including animal bone and offal)

Fish carcases and fish eggs

Untreated dairy products (may include unprocessed milk, cheese, yoghurt (processed milk already permitted for animal feed))

Unprocessed egg (raw egg and untreated egg shells); (eggs processed at an ABP plant or treated to satisfy food hygiene standards at a food manufacturing business are already permitted for use in animal feed).

3.2 Intra-species recycling and ruminant feed ban

Bovine spongiform encephalopathy (BSE) and other Transmissible spongiform encephalopathy (TSE) diseases can be caused by feeding animals with the infected remains of the same species. The epidemic of BSE in UK cattle was accelerated by the recycling of infected bovine tissues, prior to the recognition of the disease, into meat and bone meal which was subsequently added to cattle feed. In order to prevent the spread of a novel TSE or re-emergence of a known prion disease, the EU TSE and Animal By-Products (ABP) Regulations provide a combination of controls preventing the feeding of most proteins of animal origin to ruminants and other farm animal species, with exceptions. There have been recent relaxations of the TSE Feed Ban following stated aims in the EU TSE roadmap, with further relaxations due in the near future. However, key controls unlikely to be considered for relaxation in the foreseeable future include: (1) intra-species recycling i.e. the feeding of terrestrial animals of a given species other than fur animals, with processed animal protein derived from the bodies or parts of bodies of animals of the same species, and (2) the feeding of animal proteins to ruminant animals, with exceptions. The final risk estimates of the risk assessment are provided for two model systems:



3.3 Processing standards for producing animal feed from food waste

The feeding of waste food to pigs and poultry is a traditional practice that is conducted in a number of countries. A summary of temperature control criteria for processing food waste in these countries is provided in Table 1. Swill feeding is a particular practice that is specifically recognised for its role in animal disease transmission (OIE, 2011). Under the OIE terrestrial code, the standard setting body for international trade in animals and animal products, controls and surveillance measures must be put in place for the safe feeding of swill (containing animal products) to pigs. In addition, each port and international airport

1 Meat and meat products includes fresh meat, mincemeat, meat that has been processed in some

manner, e.g. bacon, ham, or salami, meat preparations (meat with seasonings or additives), meat pies, pasties, meat rolls, and other products of animal origin including blood residues in the meat, animal bone and offal.

16

should ideally be provided with equipment for the sterilisation or incineration of ship and aircraft waste or any other material deemed dangerous to animal health entering via the port (OIE, 2011). In 2005, in Japan the feed ban was amended to allow the use of proteins derived from swine and poultry in feed for swine and poultry. Conditions include that processing takes place where no ruminant materials are handled (Kusama et al., 2009). A certification system for swill feeding was introduced in 2009 for Ecofeed produced from food waste including domestic scraps and catering waste (Sugiura et al., 2009). Recommended processing for raw materials containing meat is 70°C for 30 minutes or at 80°C for 3 minutes, with resulting feed for pigs and poultry only. The Biosecurity (Meat and Food Waste for Pigs) Regulations 2005 in New Zealand regulates the feeding of food waste that contains meat or comes into contact with meat products. The regulations require that waste food is heated to 100 °C for 1 hour, or treating it to an alternative standard that has been approved by the Ministry for Primary Industries (MPI) Director-General (MPI, 2013a). Exempted foods include rendered materials, egg and egg products, milk and milk products. Production and feeding swill do not require licenses. If food waste is collected from a trade source (such as a hospital, a school, a supermarket or a food business) the supplier may request written confirmation that material will be processed according to the rules. Farmers that feed their animals swill are recommended to request confirmation from swill suppliers that the feed has been treated according to the rules, though this is not a statutory requirement. Feeding non-compliant food waste to pigs is an offence with the fine of $5,000 for individuals and $15,000 for corporations (MPI, 2013a). Table 1: Criteria for processing food waste into animal feed

Processing conditions Temperature Time Other Reference

Country/organisation Cuba 121 °C 30

minutes

1.0 to 1.5 atmospheres, 80 mm particle size

FAO, 1997

FAO/OIE 100 °C 1 hour - FAO/OIE, 2011

Great Britain (prior to 2001)

100 °C 1 hour

Japan (Ecofeed) 70°C 30 minutes

- Sugiura et al., 2009

80°C 3 minutes

-

New Zealand 100 °C* 1 hour* - MPI, 2013a

USA 100 °C 30 minutes

- APHIS, 2009

* or an alternative method approved by the Ministry for Primary Industries (MPI) Director-General

17

However, New Zealand has strict import controls. Border controls were strengthened in the 1990s with an estimated 20% of all consignments currently physically inspected and 100% of all incoming passenger baggage either X-rayed or searched, to limit incursions of illegally imported meat and meat products (MAF, 2001). All waste food from airport and ship's waste is incinerated or steam sterilised. Regular audits are conducted to monitor compliance. All facilities dealing with quarantine refuse are located in areas where there is a MAF presence, and most are visited and checked at least once a week by MAF inspectors (MAF, 2001). In the Unites States, the Federal Swine Health Protection Act (SHPA) regulates the feeding of food waste containing meat or animal materials to pigs in the USA. This Act requires registration of swill processors, and that the swill be heated throughout at boiling temperature (212°F or 100°C at sea level) for 30 minutes. Other state regulation may also apply with specific handling processes required or limiting those establishments where food waste can be collected. As of March 2010, 28 states prohibited swill feeding with 22 states permitting the route (APHIS, 2010). In 2007, this accounted for 2,722 pig producers swill feeding (3%), and producing approximately 0.12% of the marketed pigs (APHIS, 2009). The temperature controls are based on evidence in the literature for inactivation of pathogens from heating meat throughout at 167 °F (75°C) for 30 minutes (McKercher et al., 1974; Edwards et al., 2000; Williams Report, 2003). A margin (100°C required) is provided to address the fact that “larger pieces of meat may take longer than smaller pieces to reach that temperature throughout. By requiring that garbage be heated at boiling throughout for 30 minutes, the regulations …ensure that meat has been heated to a temperature sufficient to inactivate disease organisms of concern” (APHIS, 2009). There are two methods preferred for heat treatment – direct fire and stream injection (USDA/APHIS/VS, 1990). The direct fire method heats a cooking vat and is therefore more appropriate for small scale production, with steam injection for even heating for larger operations. Exempted foods include rendered products, bakery waste, sugar products, eggs, domestic dairy products, and certain domestic fish (APHIS, 2009). Such controls are subject to change. As part of the USDA preparedness for a foreign animal disease incursion into a US territory, those processors licensed to swill feed are required to contact the state regulatory agency to determine whether there has been a ban placed on feeding swill to animals during an outbreak (USDA, 2011). In the time available, three processing criteria across a broad range of temperatures were selected for investigation in the risk assessment with heat treatment considered as the only processing method.

The baseline of 100°C for 1 hour was selected as the regulatory standard in GB before 2001.

An upper control was selected, based on a simplified ABP method 4 of 30 minutes at 130°C which may destroy certain spore forming bacteria.

A lower control of 30 minutes at 70°C was selected. Above this temperature important proteins are denatured and therefore there would be nutritional advantage in the selection of a lower temperature.

There may be other processing steps involved with producing the animal feed which may also reduce the infectivity present, for example, drying of the product. However, the effect of these stages is not considered.

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4. HAZARD IDENTIFICATION The hazard identification involves identifying the pathogenic agents associated with the selected product types that could potentially produce adverse consequences in livestock. A list was compiled of the most important animal health pathogens (viruses, prions, bacteria and fungi) by combining those livestock pathogens listed for cattle, sheep, goats, pigs, poultry, camelids, horses, and farmed deer by the OIE (former list A and B) and Defra, together with any additional pathogens identified by expert opinion (APHA, pers. comm. 2014). The full pathogen list is provided in Appendix 1. Each pathogen was assessed, as to the significance of transmission to susceptible livestock, via ingestion of each of the relevant product types. Considerations included the probability of viable pathogen being present in the commodity, the survival or persistence of the pathogen in the commodity post slaughter, or in the case of dairy products, survival during any processing phases such as the production of cheese and yoghurts, and finally the probability of transmission of the pathogen by ingestion. For farmed fish, there are several exotic pathogens, which may be found in the fish carcase and eggs from infected fish that may enter food waste. From reviewing OIE fish list diseases and those of concern to Defra, these pathogens include Epizootic Haematopoietic Necrosis, Epizootic Ulcerative Syndrome, Infectious Salmon Anaemia, Infectious Haematopoietic Necrosis, Viral Haemorrhagic Septicaemia, Spring Viraemia of Carp and Oncorhynchus

masou virus disease. At temperatures over 56C these exotic pathogens are inactivated. However, the endemic pathogen Infectious Pancreatic Necrosis (IPN) would persist. Therefore, selection of IPN should provide a margin of safety when considering inactivation of fish diseases during thermal processing (Cefas, pers. comm. 2014). The key criteria applied to the full pathogen list were: (1) pathogen identified as a specific virus, prion, fungi or bacterium (parasites were excluded), (2) pathogen currently exotic to Britain (with the exception of IPN, as explained above), and (3) it was assessed overall that that there was a non-negligible probability of transmission, through the relevant meat/fish/dairy/egg product via the import pathways, to cause disease when ingested as feed by susceptible livestock. This resulted in the pathogens presented in Table 2 to be included in the risk assessment.

19

Table 2: List of pathogens to be included in the risk assessment Common name Affected livestock Product type

Pathogen Bacteria 1 Bacillus anthracis

Anthrax Most mammals and several

species of bird Meat and meat products

2 Brucella sp. Brucellosis Cattle, camels, sheep, pigs (B. abortus); Sheep and goats and other wild small ruminants (B melitensis and B ovis); Pigs (B suis)

Untreated dairy products and meat and meat products

3 Salmonella (S. Gallinarum)

Fowl typhoid Domestic and wild birds Meat and meat products and unprocessed egg

Prions 4 Chronic Wasting

disease Prion protein

Chronic wasting disease (CWD)

Deer Meat and meat products

Viruses 5 Arteriviridae,

Arterivirus Highly pathogenic - Porcine reproductive and respiratory syndrome (HP-PRRS)

Domesticated and wild pigs Meat and meat products

6 Asfarviridae Asfivirus

African swine fever (ASF)


7 Birnaviridae, Aquabirnavirus

Infectious pancreatis necrosis (IPN)

Primarily trout and salmon

Fish carcases and fish eggs

8 Coronaviridae, Alphacoronavirus

Highly pathogenic - Porcine epidemic diarrhoea (HP-PED)


9 Flaviviridae, Pestivirus

Classical swine fever (CSF)


10 Herpesviridae, Varicellovirus

Aujeszky's disease (AD)


11 Picornaviridae, Aphthovirus

Foot and mouth disease (FMD)

Cattle, sheep, pigs, goats, deer, and camelids

Meat and meat products and untreated dairy products

12 Retroviridae, Deltaretrovirus

Enzootic bovine leucosis (EBL)

Cattle Meat and meat products and untreated dairy products

13 Orthomyxoviridae, Influenzavirus A

Highly pathogenic avian influenza (HP-AI)

Mainly domestic and wild birds

Meat and meat products and unprocessed egg

14 Paramyxoviridae, Avulavirus

Newcastle disease (ND)

Domestic and wild birds Meat and meat products and unprocessed egg

15 Poxviridae, Parapoxvirus

Sheep pox and goat pox (SPP & GTP

Domestic and wild sheep and goats

Untreated dairy products

16 Picornaviridae, Enterovirus

Swine vesicular disease (SVD)


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5. MODEL OVERVIEW

The risk assessment has been divided into three modules (sections) titled food waste, feed processing and consumption. The parameters requiring estimation within each of the modules are shown in Figure 1. Each of these parameters and any associated uncertainty are described in each of the subsequent sections, with a summary table of input values provided in Table 7.

21

Figure 1: Overview of the risk assessment framework

Reduction in infectivity from processing at 70ºC, 100ºC,

and 130ºC

Proportion of legally imported and domestically produced

products infected per year as compared to illegally imported (%)

Food w

aste

Proportion of legally imported and domestically produced

products infected per year as compared to illegally imported (%)

Co

nsu

mp

tion

Feed

Pro

cessing

Number of loads of

feed available

processed from

food waste (loads

per year)

Amount of illegally imported, infected products per year

(kg) Amount of infected products entering GB

collected waste food per year by source (kg)

Proportion of pathogen survival post handling (%)

Concentration of oral infectivity in food waste

by source by temperature processed (Oral

ID50/kg)

Proportion of food entering collected waste food (%)

Daily amount of food waste consumed by

species (kg)

Dose consumed per

load (oral ID50)

Probability of infection per load

Mean oral ID50 to initiate infection (Oral ID50/ID50) Amount of source waste materials collected per year (kg)

Titre of infectivity in those positive tissues (ID50/kg)

Proportion of food waste diverted to feed processing (%)

Proportion of waste food fed to different livestock feed

(%)

Proportion of exposure to accidental contamination of cooked feed with raw (%)

Probability of exposure given segregation or segregation

failure (%)

Probability of animal infection per year in GB

22

6. RELEASE ASSESSMENT FOR FOOD WASTE The release assessment determines the likelihood of entry of exotic disease and describes the biological pathways necessary for that hazard to be introduced into the different streams of waste food. There are a number of ways by which exotic pathogen hazards could enter food material fit for human consumption. An infected animal could be slaughtered overseas, with contaminated foods imported legally or illegally into GB. Alternatively, the disease may enter through the import of an infected live animal subsequently slaughtered in GB for consumption or disease could enter by another pathway and lead to the infection of a domestically reared animal which is subsequently slaughtered for consumption without detection by GB surveillance. Alternatively, an import pathway could involve live migratory birds or wind borne/insect transmission transferring vector borne disease to domestic livestock from affected parts of Europe or contaminated fomites including returning haulage vehicles. The entry pathways for incursion of exotic disease and subsequent contamination of food waste are shown in Figure 2. The probability of incursion via each of these pathways will be dependent on the individual characteristics of the hazard (Hartnett et al., 2004) and may be dependent on various import patterns which will vary between countries and between years.

Contaminated legal/

illegal

unpasteurised dairy

products

Contaminated legal/

illegal meat/meat

product import

Contaminated

imported fomite

Infected legal/illegal

live animal import

Domestic kitchen,

hospital school,

canteen, fast food

outlet, restaurant

Supermarket, food

retailer, food

manufacturer

Disposal via former

foodsDisposal via

catering waste

Contact and

infection of livestock

on farm

Infected animal not

detected at abattoir

Infected migratory

birds, windborne

transmission

Contaminated legal/

illegal untreated

eggs

Contamination of

UK meat/eggs/diary

products

Infected UK animal

not detected on

farm

Pathogen survival in

products post (any)

processing

Pathogen not

consumed and

survives disposal

Pathogen survival in

products post (any)

processing

Figure 2: Entry pathways for exotic disease incursion into GB

23

6.1 Amount of infected products entering British waste food per year (kg)

The amount of infected products entering British waste food per year is dependent on (1) the amount imported or domestically raised (kg), and (2) the proportion of this material placed in waste that is centrally collected (%), as given by:

𝑁𝑖𝑛𝑓𝑤𝑎𝑠𝑡𝑒𝐶𝑆= (𝑁𝑖𝑙𝑙𝑒𝑔𝑎𝑙

𝐶∗ 𝑃𝑖𝑙𝑙𝑒𝑔𝑎𝑙𝑤𝑎𝑠𝑡𝑒𝑆

) + ((𝑁𝑙𝑒𝑔𝑎𝑙𝐶+𝑁𝑑𝑜𝑚𝑒𝑠𝑡𝑖𝑐𝐶) ∗ 𝑃𝑙𝑒𝑔𝑎𝑙𝑤𝑎𝑠𝑡𝑒𝐶

),

In the time available, three of the routes deemed to be the most likely for entry of the hazards identified were investigated: the amount through illegal import, 𝑁𝑖𝑙𝑙𝑒𝑔𝑎𝑙𝐶

, legal

import, 𝑁𝑙𝑒𝑔𝑎𝑙𝐶, and domestic production 𝑁𝑑𝑜𝑚𝑒𝑠𝑡𝑖𝑐𝐶. Each product type was individually

considered where c denotes commodity from 1 to 5, 1=meat, 2=fish, 3=dairy, 4=eggs, 5= live animals (for meat). Three waste food source materials are identified by s from 1 to 3, where 1=domestic kichen catering waste, 2=catering waste from restaurants, and 3=former foods. The values and distributions used are summarised at the end of the risk assessment in Table 7.

6.1.1 Estimated amount of illegally imported contaminated products entering GB per year (kg)

The weight of infected illegally imported meat and meat products entering GB has been previously estimated for African swine fever (ASF), classical swine fever (CSF), foot and mouth disease (FMD), and swine vesicular disease (SVD) (Hartnett et al., 2004). The highest estimated contaminated weight was for CSF with a mean of 263 kg per year (90% 7.5, 794) given several model assumptions and data gathered up to 2004. However, the amount of contamination varied by hazard and product type/species. For ASF the contaminated weight was an estimated mean of 0.046 kg (90% 0.007, 0.138) and for SVD a mean value of 0.007 kg (90% 0.002, 0.0021) (adapted from Hartnett et al., 2004). It needs to be highlighted that there is a high degree of variability in this parameter for different pathways at different times. The prevalence of CSF has reduced since 2004, however, ASF has probably increased. In the risk assessment, it is assumed that for each pathogen, the estimated weight of infected meat illegally imported, 𝑁𝑖𝑙𝑙𝑒𝑔𝑎𝑙1

is equal to that estimated for

CSF. Uncertainty about this parameter is described using a log normal distribution, truncated at 0. There are little data on the annual amount of illegally imported dairy, fish, and eggs that are infected entering Britain. With no further information, it was assumed that the proportion of illegal fish, dairy and eggs imports that are contaminated was the same as the proportion estimated for meat (i.e. the ratio of contaminated meat to seized meat is equivalent to the ratio of contaminated fish to seized fish). Given this assumption, the amount of illegally imported and contaminated dairy, fish and eggs entering GB is given by:

𝑁𝑖𝑙𝑙𝑒𝑔𝑎𝑙𝐶= 𝑁𝑖𝑙𝑙𝑒𝑔𝑎𝑙1

∗𝑊𝑖𝑙𝑙𝑒𝑔𝑎𝑙𝐶

𝑊𝑖𝑙𝑙𝑒𝑔𝑎𝑙1

,

where c denotes commodities 2, 3 and 4, and 𝑊𝑖𝑙𝑙𝑒𝑔𝑎𝑙𝐶 is the average weight of seized

commodity over the last six years in GB. Over the last six years, on average, 67,657 kg of illegal meat has been seized, whilst 37,198 kg of fish, and 48,924 kg of dairy and eggs have been detained by UK Border Agency (Defra, 2013). There are very few seizures of eggs and egg products (UK Border Agency, pers. comm. 2014). From an analysis of seizure data from 2013, approximately 3.4% of the total weight of dairy and eggs was attributed to eggs. With

24

no further information, 𝑊𝑖𝑙𝑙𝑒𝑔𝑎𝑙3 was estimated as 47,260 kg, whilst for eggs, 𝑊𝑖𝑙𝑙𝑒𝑔𝑎𝑙4 was

estimated as 1,663 kg. There are little data on the level of illegally imported live animals entering GB for slaughter that are infected. From discussions with GB import officials, the probability of large numbers of illegal landings was considered low as there are not significant financial drivers. Instances where a legal requirement concerning a listed import has not been met do occur, normally where inaccurate or incomplete information is provided to authorities. In absence of any further information, it is assumed the proportion of illegal live imports that are infected and enter the GB slaughter chain undetected is 1% of the amount estimated for illegally imported meat.

6.1.2 Estimated amount of legally imported contaminated products entering GB per year (kg)

In 2012 the UK imported 35% of all beef and beef products consumed2 (406,000 tonnes), 36% of sheep and sheep products (100,000 tonnes), 61% of pig meat and pork products (978,000 tonnes) and 35% of poultymeat (696,000 tonnes) (EBLEX, 2013, BPEX, 2013). The legal import of fish, dairy products and egg in shells are shown in Table 3. Table 3: Net weight of legal imports into UK from EU countries and non EU countries

in 2012 (UKTradeInfo, 2014) Product Weight of imports by origin (tonnes) EU Non-EU

Live fish 180 1577 Fresh, frozen or chilled fish 137,466 290,830 Cheese and curd 436,268 7,974 [Total dairy including milk, whey] 1,201,922 9,461 Eggs in shells 57,835 356

Legally imported products have to adhere to the same levels of safety as those domestically produced. Due to the presence of certain exotic diseases, there are large parts of the world where the legal export of products of animal origin to GB are not permitted. Other controls include meat inspection, ante and post mortem and to adhere to UK certification requirements which may include quarantine, pre and post import tests, and/or vaccination. The amount of legally imported meat, meat products, fish, dairy, eggs and live animals that is contaminated with exotic disease, 𝑁𝑙𝑒𝑔𝑎𝑙𝐶

, is likely to be far lower than that estimated for

illegal imports. However, the proximity of some import partners to other countries where disease is present may increase the risk when compared to animals born and reared in Britain. Taking into account the previous factors, it was assumed that the weight of legally imported products and live animals infected with undetected exotic disease was 10% of the estimated weight for illegally imported products and live animals. Uncertainty associated with this estimate was described using a betapert distribution with minimum value of 1%, and maximum value of 15%.

2 Estimated by import tonnage as a percentage of consumption and therefore may include re-exports.

25

6.1.3 Estimated amount of domestically produced contaminated products per year (kg)

For domestically produced food, born and reared in GB the likelihood of exotic pathogen hazards being present in any year, when there are no notifiable disease control measures in place is assumed to be lower than legally imported products. It was estimated that the weight of contaminated domestically produced products, 𝑁𝑑𝑜𝑚𝑒𝑠𝑡𝑖𝑐𝐶, was 1% of the amount

estimated for illegally imported products, with a range of 0.1% to 1.5% to describe associated uncertainty.

6.1.4 Estimated probability of contaminated products entering waste food (%)

The inland fate of illegally imported meat and meat products has been previously investigated in detail (Hartnett et al., 2004) as summarised in the framework in Figure 3. Based on discussion with appropriate trade and enforcement experts, illegal meat flows were divided into those driven by commercial concerns and those for personal, domestic use. The use of imported meat in the home was related to the weight of an imported consignment with larger consignments by weight being allocated into commercial distribution channels such as retailers and wholesalers. A seizure database containing the descriptions of illegally imported seizures from passenger baggage, freight and via the post was used to estimate that whilst 94% (by number) of seizures were for personal use, 74%(by weight) was used for commercial uses (Hartnett et al., 2004). It is assumed that all food imports are destined for human consumption and not other uses, for example, pet food manufacturer.

Illegal

Personal

Illegal

Commercial

Water

supply

Scavenger

bird

WholesaleStreet

Market

Domestic

Consumption

Human

FomiteSewage

Food for

Pets

Retailer

Animal feed

(Swill)

Scavenger

fox

Exposure

(Backyard Livestock)

Exposure

(Livestock)

Seized Meat

No ExposureNo Exposure

Pets

Illegal imports

Specialist

Restaurant

Landfill

IncineratorBackyardlivestock

Human

Carriage

Figure 3: Framework for the quantitative modelling of flow of illegal, contaminated meat

from import to livestock exposure (Hartnett et al., 2004) When considering the flow of illegal meat from personal and commercial sources via markets, retailers, wholesalers, and domestic use, the resulting outputs from the model according to the assumptions made were, by weight (adapted from Hartnett et al., 2004):

86.6% is consumed and therefore entering sewage

1.2% enters into general waste from street markets

26

12.3% enters food waste (comprised of 7.5% into catering waste from domestic kitchen, 2.3% into catering waste from specialist restaurants, and 2.5% into former foods from retailers and wholesalers).

Therefore, using the above, it was assumed that the probability of contaminated illegally imported meat enters food waste, 𝑃𝑖𝑙𝑙𝑒𝑔𝑎𝑙𝑤𝑎𝑠𝑡𝑒𝑠

, is on average 12.3% by weight, with

uncertainty described by a betapert with minimum value of 5% and maximum of 20%. This probability is multiplied by the respective probability of entering domestic kitchen waste, catering waste, and former foods by 61% (7.5%/12.3%), 19% (2.3%/12.3%), and 20% (2.5%/12.3%). Several food waste surveys have been conducted with varying estimates for the amount of food that is wasted by sector (refer to summary provided in FERA report, 2012). According to WRAP Household Food and Drink Waste in the UK in 2012, 10% of all meals, 10% of all dairy and 7% of all meat are wasted by households. Whilst there are data on the percentage of different products within catering and former food waste, no data could be found on the probability of certain products entering such waste. Therefore, it was assumed in the risk assessment that the probability of legally imported and domestically produced products entering food waste, 𝑃𝑙𝑒𝑔𝑎𝑙𝑤𝑎𝑠𝑡𝑒𝑐

, is a mean estimate of 7% for meat, with uncertainty bounds

of minimum 6% and maximum 8% described by a betapert distribution. For fish, dairy and egg legal products, it is assumed that a mean 10% enters food waste, with minimum 8% and maximum 12% to describe uncertainty. This proportion is the same across all food waste types (e.g. domestic kitchen waste, catering waste and former foods).

6.2 Concentration of oral infectivity in food waste by temperature processed (Oral ID50/kg)

The concentration of infectivity for each pathogen in food waste by processing temperature, 𝐼𝑐𝑜𝑛𝑐𝑃,𝐶,𝑆,𝑇 is dependent on (1) the amount of infected products entering British waste food

per year (kg), 𝑁𝑖𝑛𝑓𝑤𝑎𝑠𝑡𝑒𝐶,𝑆, as estimated in section 6.1, (2) the initial loading of infectivity

within those products (ID50/kg), 𝐼𝑟𝑎𝑤𝑃,𝐶, (3) the probability of survival of that infectivity post

handling (%),𝑃𝑠𝑢𝑟𝑣𝑖𝑣𝑎𝑙𝐶, (4) the conversion of ID50 units into oral doses (oral ID50/ID50), 𝐼𝑜𝑟𝑎𝑙𝑃,

(5) the total weight of food waste collected per year in GB (kg), 𝑁𝑠𝑜𝑢𝑟𝑐𝑒𝑆and finally (6) the

reduction in infectivity brought about by temperature processing of the food waste into feed 𝑅𝑡𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒𝑃,𝐶,𝑇.

𝐼𝑐𝑜𝑛𝑐𝑃,𝐶,𝑆,𝑇,𝐿 =𝑁𝑖𝑛𝑓𝑤𝑎𝑠𝑡𝑒𝐶,𝑆

∗ 𝐼𝑟𝑎𝑤𝑃,𝐶 ∗ 𝑃𝑠𝑢𝑟𝑣𝑖𝑣𝑎𝑙𝐶

𝐼𝑜𝑟𝑎𝑙𝑃,𝐿 ∗ 𝑁𝑠𝑜𝑢𝑟𝑐𝑒𝑆∗ 𝑅𝑡𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒𝑃,𝐶,𝑇

Where P refers to pathogen 1 to 16 as listed in the hazard identification, C denotes commodity, S denotes the source material, T refers to four different temperature processing criteria at 0ºC (raw), 70ºC, 100ºC and 130ºC, and L is the livestock species fed the

processed feed, from 1 to 6 representing 1= cattle and camelids, 2=deer, 3=sheep and goats, 4=pigs, 5=poultry, and 6=fish. For Newcastle disease contamination in eggs, the infectivity unit was EID50 per egg. Therefore the weight, 𝑁𝑖𝑛𝑓𝑤𝑎𝑠𝑡𝑒4,𝑆

was converted into the

average number of eggs, by dividing by the mean weight of an egg, assumed to be 60g.

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6.2.1 Initial loading of infectivity in product type (ID50/kg)

Depending on the pathogen, spread may occur from the site of initial infection through the rest of the body. As a result, meat products, milk and eggs originating from an infected animal may be contaminated. The initial loading of pathogen in products of animal origin,

𝐼𝑟𝑎𝑤𝑃,𝐶 , by each of the 16 hazards and by the relevant product type was investigated. Table

4 presents the summary of results with the review for each pathogen provided in Appendix 2. The amount of the pathogen in a product will be dependent on the product constituents and the loads in these parts by pathogen strain. In addition, the number of days post-infection, species of susceptible livestock and the organs/tissue type influence the amount of the pathogen present. Where possible a range to account for the uncertainty associated with the mean amount was estimated taking these factors into account. However, for some suscpetible species, disease, and product type combination little information was found available in the literature. For these pathogens it was assumed that, where available, that the amount was the same as measured in another product type. If other product type data was not available, it was assumed that a relatively low amount of pathogen was present, with approximately 4 logs/g or ml. Each value in Table 4 was multiplied by 1000 to convert the unit to ID50 per kg of product.

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Table 4: Summary of the initial loading of pathogens by product type from an infected animal

Common name

Product type*

Meat Dairy Eggs

B. anthracis 105 spores/g (assumption)

Brucella Not available Assumed to be 400 CFU/g

400 to 1000 FU/ml

S. Gallinarum Up to 105 CFU per carcass

Assumed to be 105 CFU/g

Not available Assumed to be 10

5

CFU/g CWD < 10

9 i.c. ID50/g (based on study in mice)

HP-PRRS 101.8

to 103.8

TCID50/g

ASF 104.25

to 108 HAD50/g

IPN 103 to 10

6 pfu/g

HP-PED Not available Assumed 1 to 10

2.15

TCID50/g

CSF 104.2

TCID50/g to 105.56

TCID50/g

AD Not available Assumed to be 10

4

TCID50/g

FMD 103.77

TCID50/g (average across species)

Between 102.2

and 106.6

TCID50/ml

EBL Not available Assumed to be 10

4 cells/g

Not available Assumed to be 10

4

cells/g

HP-AI 102.8

to 108.5

EID50/g

mean 104.9

EID50/g (min 10

1.8 EID50/g, max 10

5.6

EID50/g)

ND 106.4

to 106.8

EID50/g

100.97

to 106.7

EID50 per egg

SPP & GTP Not available Assumed to be 10

4

TCID50/g

SVD 103.19

pfu/g

*Each value was multiplied by 1000 to produce units of infectivity per kg

6.2.2 Probability of pathogen survival post handling (%)

Adequately cooked meats and meat products in food waste may inactivate pathogens prior to any subsequent processing. The average discard rate of uncooked meat from domestic kitchens and catering facilities has been determined from various telephone exercises and other surveys. The percentage of uncooked meat discarded from domestic kitchens may be approximately 3.4% (Gale, 2002). In addition to thermal processing, there may a decay of the pathogen due to the passing of time in storage, either at ambient temperatures, for

29

example during importation in passenger baggage, or in chilled conditions in a fridge within a domestic setting or commercial. Survival of CSF, FMD, SVD, and ASF post handling in homes has been previously estimated as 15% (Corso, 1997). For all three source materials, food products in the waste stream may contain cooked, partially cooked and uncooked products, stored for various periods at temperatures from ambient to freezing. With no further information, In the risk assessment the average probability of survival post handling, 𝑃𝑠𝑢𝑟𝑣𝑖𝑣𝑎𝑙𝐶, was described as being equally likely between 3% and 15% within a uniform

distribution.

6.2.3 Conversion of ID50 units into oral doses (oral ID50/ID50)

A literature review was conducted for each of the selected pathogens from the hazard identification to obtain published data on the oral dose required to initiate infection. Table 5 presents the summary of results for 𝐼𝑜𝑟𝑎𝑙𝑃,𝐿 with the review for each pathogen provided in

Appendix 3. In order to estimate the dose, experiments have been carried out with a known amount of pathogen fed to a number of recipent animals, with subsequent investigation of the number found infected. The oral ID50 dose is defined as the dose required to infect 50% of exposed animals. However, some experimental work has been aimed at estimating the Minimum infectious dose (Mid) defined as the lowest dose found to initiate infection. In contrast for vaccination studies, the aim is often to produce 100% infection, and accordingly doses are higher. The route of infection influences the dose required. Experiments have been undertaken with intranasal injection, cutaneous injection and injection into the peritoneal space. Such methods often reduce the amount of pathogen required to initiate infection as there is a by-pass of the aggressive gastrointestinal conditions experienced following oral administration. In this section, the consequence of exposure to oral dose has been explored for doses via ingestion. There may be specific events in the feeding of livestock with processed feed (potentially more likely with liquid feed than a dry coarse meal) where the feed may become aerosolised. In these cases, animals exposed may be infected by doses lower than the oral dose reviewed here. It should also be noted that animals in a poor state of health when compared to experimental animals may also have a lower dose required to initiate infection. Where pathogens affect a number of different species, values for the species specific oral dose were searched in the literature. However, data were not found for all susceptible species – pathogen combinations. Therefore, risk estimates for some pathogens were only provided those species where an oral dose was found. For example, for anthrax spores, final risk estimates are only provided for pigs and sheep.

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Table 5: Summary of the average oral dose required for infection from ingestion Oral dose to infected 50% of exposed animals

B. anthracis Between 51, 000 and 200,00 spores (Mid) sheep Between 10

7 and 10

10 pigs

Brucella sp. Not known, approximated 2.5 x 107 cells B. abortus and B. suis

2.5 x 107 to 5 x 10

7 cells for B melitensis

6.6 x 107 cells for B ovis

S. Gallinarum

2.04 x 108 CFU (LD)

CWD 150 g†

HP-PRRS Average 105.3

TCID50, 95% CI 104.6

and 105.9

ASF 104.3

HAD ID50

IPN

Between 103 pfu** and 10

4 pfu

HP-PED

102.0

TCID50

CSF

Average 105 with 95% CI 10

3.57 to 10

5.8 TCID50

AD

105 TCID50

FMD 105 TCID50 Pigs

105.8

TCID50 to 106 TCID50 Cattle

EBL

105 cells

HP-AI

103.9

*EID50

ND 104 EID50

SPP & GTP

106 TCID50

SVD 106.8

pfu

† estimate associated with considerable uncertainty due to extrapolations with BSE

* intranasal dose **intraperitoneal dose

Mid – minimum infectious dose reported in the literature; CFU – colony forming units

LD – Lethal dose; TCID50 – tissue culture ID50, pfu – plaque forming units; EID50 – egg ID50

6.2.4 Total weight of food waste collected per year (kg)

Approximately 15 million tonnes of food waste in total is generated annually with about half generated by domestic waste (FERA, 2012); however, not all this waste is collected separately from other waste materials. The most recent estimate of domestic food waste separated from general waste and collected by Local Authorities (4.6 x 109kg) is around 21% lower than two earlier surveys carried out in 2007 and 2008 (FERA, 2012). Commercial and industrial businesses produced a total of 3.76 x 109kg of separated and collected animal and vegetable waste in 2009. In the risk assessment, the amount of food waste collected, 𝑁𝑠𝑜𝑢𝑟𝑐𝑒𝑆, from S=1, domestic kichen catering waste is assumed to be 4.6 x 109kg, whilst for

the combined total for catering waste from restaurants and former foods (S=2+3) is assumed to be 3.76 x 109kg. With no further data available to separate catering waste from restaurants and that generated as former foods, the risk estimate for these two streams are provided together, and termed ‘commerical food waste’.

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6.2.5 Reduction in infectivity from processing of food waste into feed (%)

A literature review was conducted for each of the selected pathogens from the hazard identification to obtain published data on their thermostability. The published data included a variety of different media and strains, which affected the inactivation rates. It was assumed that all the food waste was heated internally to the set temperature for the required time. Therefore, for certain products, grinding/mascerating to a particular particle size to ensure consistent heating would be required. The detailed review by pathogen is provided in Appendix 4 with the summary for the values of 𝑅𝑡𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒𝑃,𝐶,𝑇 used in the risk assessment

for each hazard provided in Table 6. Inactivation is defined as the complete inactivation of the pathogen regardless of dose or concentration in the product. Table 6: Summary of the reduction in infectivity by product type post temperature

processing Common name

Processing criteria

70°C for 30 minutes 100°C for 1 hour 130°C for 30 minutes

B. anthracis spores

No effect Bone meal no effect; significant reduction in milk. Assumed to

be 3 log reduction average

Inactivated (wet heat) if bone meal reliably

excluded

Brucella sp. Inactivation Inactivation Inactivation

S. Gallinarum

Inactivation may not occur in high-fat foods. Assumed

to be 3 log reduction

Inactivation Inactivation

CWD No effect No effect 3 log reduction

HP-PRRS 1 log reduction 15 log reduction Not available. Assumed inactivation

ASF Inactivation Inactivation Inactivation

IPN Assumed to be 2 log reduction

25 log reduction Not available. Assumed inactivation

HP-PED Inactivation Inactivation Inactivation

CSF Inactivation Inactivation Inactivation

AD 30 log reduction Not available. Assumed inactivation

Not available. Assumed inactivation

FMD 5 log reduction Inactivation Inactivation

EBL Inactivation Inactivation Inactivation

HP-AI Inactivated in meat. 2-3 log reduction in egg products


ND 21 log reduction in meat. 4 log reduction in egg

products


SPP & GTP Not available. Assumed to be inactivated


SVD Inactivation Inactivation Inactivation

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7. EXPOSURE ASSESSMENT TO ANIMAL FEED The exposure assessment consists of describing the pathway routes necessary for exposure of animals to the hazards identified in food waste. The exposure routes by which different target animals (pigs, poultry and farmed fish) and other susceptible non-target animals could be exposed to animal feed are evaluated assuming a theoretical industrial animal feed production process. Backyard swill feeding or intentional commerical illegal feeding of swill is not included in the assessment. The feeding of pigs, poultry and fish with products of animal origin in waste food is currently not permitted in Britain, but exceptions are allowed. Such exceptions include certain bakery and confectionary products containing specified low risk animal products, and milk processed according to requirements within the ABP Regulations. Animal feed diets are formulated to provide appropriate nutrition to meet the requirements or the species and age of animal for which they are intended. The ingredient supply chain can be diverse with feed rations comprising of a varied combination of components such as grains, pulses, oilseed residues, root crops, fibrous material and some animal by-products, which are eligible for feeding. Large volumes of feed materials are imported from Third Countries to satisfy, in particular, the need for protein in the diet. In 2012, AHVLA estimated from data gathered from UK ports (Harris, unpublished) that 6,773,771 tonnes of bulk feed entered through UK ports annually, including soya and sunflower from South America, palm kernel and molasses from the Far East, citrus pulp and corn gluten from North America, sunflower from the Ukraine and sugar beet from the Middle East. The EU is acknowledged to be low in protein sources for use in farm animal feed. The total EU protein crop production currently occupies only 3% of the Union's arable land and supplies only 30% of the protein crops consumed as animal feed in the EU, with a trend over the past decade towards an increase in this deficit (European Parliament, 2011).

Farm animals require a balanced mix of feed materials to satisfy their nutritional requirements. Pig, poultry and fish diets, which we are considering here, are produced in either a pellet form, produced at a feedmill, or as a meal (unpelleted) form, which can also be produced on farm using milling and mixing equipment (static or mobile). Blending plants are an additional type of business, where bulk feed materials are blended together, rather than specifically mixed. The resulting end product is sent directly for on-farm use or to feedmills to include as an ingredient in a more complex compound feed. There are also specialist manufacturers of premixes, additives, vitamins and minerals. There are businesses, which currently source eligible bakery and confectionary goods. Some only de-package and produce a course meal from the intake material and forward this on to others, who mix it with other similar products, imported vegetable proteins, cereals and co-products from the food industry to blend into biscuit meals and sweet starches. It is envisaged, if legal, processed catering waste/foodstuffs containing meat/ meat products / fish/ dairy etc. may enter pig, poultry or farmed fish feed markets as:

a dried product (coarse meal), which could be sent to a blending plant, feedmill or direct to farm; or

in liquid form for feeding to pigs directly on farm. The pig industry is the only one with historical and current mechanisms for delivering the feed in liquid form directly to the animal. It is assumed that the poultry and fish feed industry would not be interested in this method of delivery.

33

A simplified example of a typical feed manufacturing process can be seen at a feed mill that manufactures compound feed, where feed materials are routinely treated to improve digestibility, storage and handling and to reduce levels of contaminants (microbiological/ fungal etc.). The manufacturing chain typically comprises of the following steps:

Ingredients are received at the feed mill. These may be bulk plant proteins, such as soya, rapeseed; derived products, such as fishmeal (for inclusion only in non-ruminant rations); vitamins, additives, minerals; biscuit meals (mixtures of eligible surplus foodstuffs) etc. These are stored in raw material hoppers/ bags or bulkers.

The ration is then formulated, ground to a consistent particle size (where applicable) and mixed.

This mix is then treated (cooked) to improve digestibility and longevity of the product. Typically this is not a sterilisation step, although it may contribute to a reduction in bacterial/viral load. Feed mills generally have fully automated systems to control formulation and treatment of rations.

Following this step the product may be pelleted, cooled and stored and packed prior to dispatch.

In this assessment three food waste source material scenarios have been considered thus far. These vary with regards to the estimated risk of contamination with exotic pathogens, and on the ability to segregate food waste as required by an intra-species recycling ban or the ruminant feed ban:

Domestic kitchen waste collected as part of domestic refuse collection. This would comprise of mixed foodstuffs derived from a mix of species which cannot be easily segregated by species.

Catering waste originating from restaurants, canteens, fast food premises and retail premises. It may be possible, given adequate risk management measures, to segregate some of this waste stream into individual species type depending on the point of origin and the potential for identification of products either visually or via labelling of the product i.e. chicken waste from a fast food outlet only serving chicken products.

Food production waste from food manufacturing processes. It may be possible, given adequate risk management measures, to segregate some of this waste stream into species type depending on the point of origin and the potential for identification of products either visually or via labelling of the product i.e. chicken waste from a manufacturer making only chicken products.

Figure 4 displays the flow of catering waste collected from routine domestic kitchens as part of local authority waste collection via dedicated transport through to processing and farm use. Two potential streams are shown. The first represents a liquid (traditional ‘swill’ type) product transported via a closed system from the processing facility directly to the farm. The second outlines the steps involved in producing a dried product (coarse meal) that is then handled as a traditional feed ingredient by a blender, feed mill or on-farm mixer. The flow of waste from restaurants, canteens, fast food outlets, retail shops or factories producing food for human consumption is shown in Figure 5. The process is similar to that of the domestic kitchen waste. However, there is scope for an additional separation stage of products at source and during transportation allowing the collected waste to be checked for compliance with the correct separation at a picking line prior to processing. The potential for segregating waste products is highlighted on the pathway diagram.

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Figure 4: Pathway outlining flow of food waste from domestic kitchen waste to farm

(NB. product from a dedicated facility or a dedicated line can be either dried or remain in liquid form)

Farm

Dedicated transporter

Compounder

Liquid product Enclosed pipework to vehicle

Dedicated tanker

Farm Enclosed pipework from vehicle On farm store Addition of additives Restricted access

On- site drier Dried product


Feed Mill Dedicated storage physically separate from ruminant feed materials/ ingredients Adequate separation between ruminant and non-ruminant lines Enclosed lines/ separation/ separate buildings

Blender


Waste collection Food waste bins collected by local authority contractors


Bulking point Controlled storage

Dedicated transporter If not on same site

Dedicated processing facility

Store Macerate and process Store

Dedicated line within a processing facility with adequate separation from other

activities Store Macerate and process Store

35

Figure 5: Pathway outlining flow of food waste from shops, restaurants and food factories to farm

Waste collection Separate collection bins (identifiable)


Picking line and de-packaging Removal of misclassified batches Controlled storage

Dedicated transporter If not on same site

Dedicated processing facility


Dedicated line in processing facility with adequate separation from

other activities


Liquid product Enclosed pipework to vehicle

Dedicated tanker

Farm Enclosed pipework from vehicle On farm store Addition of additives Restricted access

On- site drier Dried product


Feed Mill Dedicated storage physically separate from ruminant feed materials/ ingredients Adequate separation between ruminant and non-ruminant lines Enclosed lines/ separation/ separate buildings

Blender Compounder

Farm



36

7.1 Routes of exposure of animals to processed animal feed

From reviewing Figure 4 and 5 it can be seen that there are a number of sequential steps required from collection of food waste to the subsequent feeding to pigs, poultry and farmed fish. Operation of controls in ABP processing plants and the swill feeding controls before the ban on swill feeding in 2001 can also be considered when assessing plausible requirements to prevent access of susceptible animals to raw waste and contamination of processed product with raw product: The key risks to avoid at all steps in the process are:

Exposure of any livestock, fish, or wildlife to collected raw waste food.

Cross contamination of cooked processed product with raw materials.

Contamination of streams dedicated for ruminant feeds with cooked processed product.

Contamination of streams dedicated for non-ruminant feeds with same species materials i.e. intra-species recycling.

Mislabelling of meat products by species (for example pig meat labelled as beef).

There are various points in the supply and processing chain at which exposure to livestock, wildlife or cross contamination could occur including, for example: 1. At the source material premises:

Collected raw food waste uncovered/insecure; permitting wildlife scavengers, for example, birds, wild boar or deer.

Collected raw food waste held where livestock are present and which may gain access

Inadequate separation during storage.

Inadequate separation of meat/ meat products entering specified labelled bins.

Inadequate cleaning of storage bins.

Fraudulent species labelling (for example, pig meat mislabelled as beef).

2. At processing plant:

Access by farm animals to raw food waste, if farm animals are allowed to be located on the same site.

Inadequate separation during bulk storage of incoming material or finished product due to use of equipment, such as front end loaders, or inadequate distances between stored materials.

Failure of heating element and temperature monitoring equipment leading to the required core temperature not being achieved.

By-pass of raw incoming material into cooked processed material, due to incorrect use of equipment, fomites or contaminated operator protective clothing or footwear.

Entry point of labelled bins – material sent down wrong production line.

Large scale collected raw food waste uncovered permitting wildlife scavengers.

Leachate/wastewater from large scale raw food waste entering water supplies with downstream susceptible livestock, fish or wildlife access.

Use of the same production line for material sourced from more than one species without adequate clean down.

Failure of quality control checks – inadequate scrutiny of documentation and/or pickers on picking line fail to reject unidentified or wrong material either through incompetence of the operators or presence of masking factors (for example, sauces).

37

Failure of PCR analysis to detect protein of wrong species (limitations of specificity, sensitivity or the presence of PCR inhibitory factors).

Inadequate separation during package or bin storage, due to method of storing or damage to packaging.

3. At blending plant:

Inadequate separation during bulk storage of incoming material or finished product due to use of equipment or inadequate distances between stored materials.


Use of same production line or mixer equipment without cleaning down – clean-down between consignments is usually not practical.

Contamination through fomites or operator clothing, utensils or equipment.

Incorrect labelling of packaging or identification of bulk compound feed or processed cooked product.

4. At feedmills:

Inadequate separation during bulk storage of incoming material or finished product due to use of equipment or inadequate distances between stored materials.


Using a bulk store without adequate cleaning between consignments.

Use of same production line or mixer equipment, without cleaning down – clean-down between consignments is usually not practical on a feed production line due to ‘hang-up’ areas i.e. areas where small amounts of feed or dust can accumulate, despite movement through the system of material.



5. On farm:

Inadequate separation during bulk storage of incoming material or finished product due to use of equipment or inadequate distances between feed materials.

Using a bulk store without adequate cleaning between consignments.


Use of same production line or mixer equipment.



Failure to prevent direct access to non-target species including inappropriate measures in place to prevent accidental feed access by non-target species, due to animals breaking into storage or feeding areas.

Operator error in using wrong feed for wrong species.

6. Transport at various stages from source premises to store, to processing plant, to blending plant, to compound feedmill and to farm:

38

Inadequate separation during transit of bulk material – split loads.

Inadequate cleaning between different bulk consignments.

Damaged packaging and inadequate separation during loading.

Small storage containers (or bins) being inadequately sealed or loaded during transit.

Incorrect or incomplete documentation associated with the consignment.

7. Storage at different locations:

Collected raw food waste uncovered permitting wildlife scavengers.

Collected raw food waste held where livestock are present, which may gain access.

Inadequate separation during bulk storage of incoming material or finished product due to use of equipment or inadequate distances between feed materials.

Inadequate separation during package or bin storage, due to method of storing, equipment cleaning deficiencies or damage to packaging.

Using a bulk store without adequate cleaning between consignments. The potential risks associated with the production and feeding of waste food currently banned to animals will be dependent on the specific method of production, distribution and the effectiveness of risk management measures that are put in place.

7.2 Number of species specific loads processed into animal feed from food waste (loads per year)

The number of loads of species specific feed available to be processed from food waste (loads per year) depends on (1) the total weight of food waste collected per year, 𝑁𝑠𝑜𝑢𝑟𝑐𝑒𝑆, as

estimated in section 6.2.4, (2) the proportion of waste food diverted to feed production,

𝑃𝑓𝑒𝑒𝑑𝐿, (3) the proportion processed waste that is fed to different livestock per year, 𝑃𝑝𝑓𝑒𝑒𝑑𝐿

,

and (4) the daily amount of processed waste consumed by an individual (kg), 𝐿𝑜𝑎𝑑𝑠𝐿 as shown in the following equation:

𝑁𝑙𝑜𝑎𝑑𝑠𝑆,𝐿 =𝑁𝑠𝑜𝑢𝑟𝑐𝑒𝑆 ∗ 𝑃𝑓𝑒𝑒𝑑𝐿

∗ 𝑃𝑝𝑓𝑒𝑒𝑑𝐿𝐿𝑜𝑎𝑑𝐿

Where L is the livestock species fed the processed feed, from 1 to 6 representing 1= cattle

and camelids, 2=deer, 3=sheep and goats, 4=pigs, 5=poultry, and 6=fish. In the absence of data on the specific dry weight and nutritional value of the food waste and resulting feed in either liquid or dried product, it was assumed that the weight of food waste equalled the weight of feed consumed per day.

7.2.1 Proportion of food waste being diverted to animal feed (%)

The proportion of food waste that is collected and processed industrially into animal feed,

𝑃𝑓𝑒𝑒𝑑𝐿, is likely to be dependent on the demand. Whilst there is an adequate supply of input

food waste, the interest in waste food as a feed ingredient for pigs, poultry and fish, should regulations change, is not known with any certainty for the GB market. Prior to the ban in 2001, an estimated 82,000 to 130,000 pigs were fed food waste (Parliamentary and Health Service Ombudsman, 2007). This equates to only 1.4% to 2.4% of the 2001 standing pig population in Britain (Defra, 2014). In 2012 there were an estimated 3.794 million pigs in the GB standing population (Defra, 2013, DARDNI, 2013). FERA investigated the economics of re-cycling food waste and the feeding of food waste to farmed animals as a future option (FERA, 2012). FERA concluded that feeding livestock processed food waste may be

39

increasingly attractive as the price of arable based animal feeds increase. However, if feed from food waste costs the equivalent of conventional feed, then uptake may be less. Assuming all domestic catering waste and commercial waste was manufactured into animal feed (with no other supplementary materials), and of this, 85% of total processed feed entered the pig sector, 51.2% of the standing population of pigs could be fed for a year. This estimate was viewed as an over-estimate of the potential market demand of pig swill, particularly considering historic levels. It was considered that the mean number of pigs fed food waste would equal the same as the upper limit of historic levels at 2.4%, to a maximum of 5% of the British standing pig population. In order to implement these values in the risk assessment the proportion of food waste diverted to pig feed such that a mean and maximum number of pigs was fed, was estimated using a simulation solver function. Where both domestic and commercial sources of waste were used, a most likely proportion of 5% of waste material was diverted to feed production (minimum value 1% to a maximum of 7.5%). Where only commercial sources are used, it was assumed that the total market size is the same. This assumption permits the comparative risk of the lifting of the intra-species barrier to be made. Therefore, where only commercial sources were used, a most likely proportion of 11% of commercial waste material was diverted to feed production (minimum value 1% to a maximum of 17.2%). This range of uncertainty was described in the model using a pert distribution. In order to assess the impact of this parameter, a scenario was also performed where the amount to feed manufacture was substantially increased.

7.2.2 Proportion of feed manufactured into different livestock sectors (%)

The risk assessment scope was to assess the risk associated with the feeding pigs, poultry and farmed fish processed food waste. There are no data on the proportion of such

theoretical feed that would be processed for each of these markets, 𝑃𝑝𝑓𝑒𝑒𝑑𝐿. Historically, pigs

have been the traditional livestock sector fed food scraps. Meat by-products and poultry meal have been previously listed as inputs to fish feed, however, these are listed as ‘unconventional inputs’ (FAO, 1978). Given the industrial processing of food waste, however, standardised pelletized feed may be produced that may be applicable for feeding to poultry and farmed fish. There is considerable uncertainty associated with estimating the proportion of feed manufactured for each target livestock sector. Exposure to non-target livestock, fish or wildlife may also occur from the large scale collection of food waste and storage prior to processing. Under the previous swill regulations, it was an offence to bring unprocessed catering waste onto any premises where ruminant animals, pigs or poultry were kept, although approved swill manufacturing plants could be co-located, as a separate premises, on the same site. Under the Animal By-Products (Enforcement) (England) Regulations 2013 (& Devolved Administration equivalents), “Animal by-products, including catering waste, must not be brought on to any premises if farmed animals would have access to such animal by-products”. This “does not apply to derived products, except for—

(a)products derived from catering waste; or (b)meat and bone meal derived from Category 2 material and processed animal proteins intended to be used as or in organic fertilisers and soil improvers that do not comply with the requirements of Article 32(1)(d) (placing on the market and use) of the EU Control Regulation.”

40

In many parts of Britain, food waste is already collected as a separate waste stream by local authorities for processing by large scale plants using anaerobic digestion, composting, landfill or rendering/incineration, with associated controls in place to limit scavengers and water pollution. If carried out legally to the same level of care, the probability of livestock, fish or wildlife access to food waste during storage awaiting collection, processing, storage post processing and transportation to farm in any new system is assumed to be the same as that currently experienced under current arrangements. In other words, it is assumed that there should not be any additional risk from the collection, storage, transport and processing of food waste if carried out to the same level of care. Again it is highlighted that the risk assessment does not include the intentional ‘illegal’ feeding of unprocessed waste food on farm. However, there would be an additional risk of exposure of wildlife and non-target livestock from the feeding of pigs, poultry and farmed fish processed food waste. Deer are known to take food from bird feeders, and there may be operator error on farm in the feeding of cattle or farmed deer the feed produced for pigs or poultry. The occurrence of such accidental feeding, as opposed to the intentional illegal feeding (not considered in this risk assessment) is difficult to parameterise but is likely to occur at a low level. It was assumed that the proportion of feed fed accidentally to non-target animals (cattle and camelids, sheep and goats and deer) was equivalent to the proportion of feed where a segregation failure occurred. The probability of a segregation failure occurring is assumed to be similar in magnitude to that currently experienced under current arrangements, 𝑃𝑓𝑎𝑖𝑙𝑢𝑟𝑒 , estimated in

section 7.4.1, as a mean of 5.36 x10-4 with a minimum value of 4.6 x10-4 and maximum of 3.2 x 10-3 .This uncertainty was described using a betapert distribution. This is not an inconsiderable amount equating to, on average, 616 tonnes of feed per year fed to non-target species. Of the remaining feed, it was assumed that the vast majority would be produced for pigs, as was the case historically, with 75% to 95% of the feed assumed to be processed for pig feeding, described using a uniform distribution. Finally the remainder of the feed was thought equally likely to be processed for feeding to poultry or fish. On average, this percentage equated to 7% of the total amount of processed feed. In summary, taking into account the different feeding pathways, the estimated mean percentage fed to each species was as follows, 85% pigs; 7.42% fish; 7.42% poultry; 0.05% sheep and goats; 0.05% deer; and 0.05% cattle.

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7.2.3 Amount of processed waste consumed by livestock species per day (kg/animal/day)

Processed food waste has specific characteristics dependent on the quality of the input food waste and supplementary materials added during production. Cuba developed a national, industrially processed, swill feeding system between 1975 and1985 (FAO, 1997). Initially, the average daily amount fed to pigs weighing between 25 and 90 kg was 12 kg, and contained 18 to 22% dry matter depending on the quality of the product in each processing plant. The daily gain was never more than 450 g and the dry matter feed conversion was approximately five tons of “processed” swill to one ton of live-weight gain. With additions of molasses and dry cereal concentrate, the daily intake was reduced to 8 to 10 kg of swill and 0.8 kg of a dry concentrate ration. Eventually 400 to 500 thousand pigs were fed on this system daily (FAO, 1997). In the risk assessment, the nutrition quality of any food waste diverted to animal feed is not known, and therefore to incorporate uncertainty, it was assumed that the daily intake of processed feed was equally likely between 8 and 12 kg. Cattle were also fed with processed feed in Cuba. Each ten thousand head feedlot required 80 tons of food wastes daily (FAO, 1997). This equates to 8 kg per head per day which is the value assumed in the risk assessment. There was no information available in the literature for the average amount of processed food waste that may be consumed by farmed deer, sheep or poultry. This amount will be strongly dependent on the amount and quality of grass, hay, silage or other feed available, the breed of the animal, weight/age of the animal and maternal status. It was assumed that the amount was equivalent to the average weight of pelleted feed fed per day, of between 1.4 to 2.3 kg per deer head (Perkins, 1991), between 0.25 and 1 kg per sheep (MLC, 2006), and between 0.10 and 0.15 kg per bird (Jacob, 2011); these are described in the risk assessment by uniform distributions. Very small fish require a small feed particle size in order to feed efficiently. It was assumed that fish feed was produced in feed mills adapted for pig and poultry feed, and therefore only a medium particle size was produced for feeding to grower fish and broodstock. Using rainbow trout as an example and feeding 2% body weight of 25 g growers or feeding 1.5% of body weight of1500 g broodstock, this equated to the daily feeding of 0.5 to 22.5 g or 5 x 10-4 to 2.25 x 10-2 kg (FAO, 2014).

7.3 Dose consumed per load (Oral ID50)

The dose consumed per load is estimated by the multiplication of the concentration of oral infectivity in food waste by source by temperature processed (oral ID50/kg) as estimated in section 6.2, by the daily amount of processed feed consumed by livestock species (kg) as estimated in section 7.1.2:

𝐼𝑙𝑜𝑎𝑑𝑃,𝐶,𝑆,𝑇,𝐿 = 𝐼𝑐𝑜𝑛𝑐𝑃,𝐶,𝑆,𝑇,𝐿∗ 𝐿𝑜𝑎𝑑𝐿

Where C denotes commodity, S denotes the source material, P refers to pathogen 1 to 16 as listed in the hazard identification, T refers to four temperature processing criteria at 0ºC (unprocessed – raw material), 70ºC, 100ºC and 130ºC, and L is the livestock species fed the

processed feed, from 1 to 6 representing 1= cattle and camelids, 2=deer, 3=sheep and goats, 4=pigs, 5=poultry, and 6=fish.

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7.4 Probability of exposure given segregation, segregation failure and cross contamination of cooked materials with raw food

In this risk assessment, two situations were investigated:



For Model system 1 exposure to susceptible animals could occur from species segregation failure or contamination of product with raw food. Another exposure route would be from any viable pathogen left post processing. For Model system 2, there is no species segregation and therefore no reduction in exposure resulting from that practice. Exposure would occur from contamination of product with raw food and from any viable pathogen left post processing. A comprehensive analysis of the probability of cross contamination of streams associated with species segregation failure, 𝑃𝑓𝑎𝑖𝑙𝑢𝑟𝑒, and the probability of cross contamination of

cooked processed product with raw materials, 𝑃𝑟𝑎𝑤, at each of the seven theoretical stages outlined in the previous section 7.1 has not been conducted due to the absence of a current system in place from which these parameters can be measured. Currently certain restricted proteins are permitted in non-ruminant farm animal feed, such as fishmeal, but are banned in ruminant feed. Bakery and confectionary products containing certain products of animal origin, such as milk, fat, eggs and non-ruminant gelatine can also be used in farm animal feed. Current data derived from inspections within the National Feed Audit sampling for restricted proteins where they should not be present, may provide some insight into how effective controls would be if implemented to prevent raw food waste contamination and species segregation failures. Given correct species segregation of food waste has correctly taken place within Model system 1, exposure to pathogens may still occur where the disease affects more than one species of livestock, or where dairy and egg products may become contaminated. The reduction in exposure resulting from correct species segregation 𝑃𝑐𝑜𝑟𝑟𝑒𝑐𝑡𝑃,𝐶 has been

investigated for each pathogen and product combination. Several of the diseases are multi-species. These pathogens include anthrax spores, B. abortus, and FMDV. Eggs and dairy would not be segregated by species, so eggs contaminated with HPAI, ND and S. Gallinarum could be fed to poultry. Fish cannot be fed on the bodies or parts of farmed fish of the same species. Specifically for IPNV in fish, with no further information, the reduction in exposure imposed by the species segregation of only different species of fish is assumed to be 80%. The impact of this assumption on the risk estimates for IPN has been assessed in the scenario analysis.

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Model system 1: Implementation of intraspecies recycling barrier For each of the source materials (domestic kitchen waste, catering waste from shops and restaurants, and former foods from factories), the probability of exposure to different types of processed food waste are estimated for four routes:

1. Probability of exposure to raw material due to contamination, together with a failure to segregate correctly results in exposure for non-target susceptible animals (cattle, sheep and goats, and deer) as well as pigs, poultry and farmed fish being fed tissues from the same species. The estimated probability of exposure from this route, R=1

was 𝑃𝑒𝑥𝑝𝑜𝑠𝑢𝑟𝑒𝑃,𝐶,𝑅

= 𝑃𝑟𝑎𝑤 ∗ 𝑃𝑓𝑎𝑖𝑙𝑢𝑟𝑒

2. Probability of exposure to raw material due to contamination, downstream of correct segregation of material, leading to the feeding of pigs, poultry and farmed fish raw food waste. However, there is a reduction in exposure, as pigs are not fed with porcine tissues, and poultry are not fed with avian tissues. The estimated probability of exposure from this route, R=2 was

𝑃𝑒𝑥𝑝𝑜𝑠𝑢𝑟𝑒𝑃,𝐶,𝑅 = 𝑃𝑟𝑎𝑤 ∗ (1 − 𝑃𝑓𝑎𝑖𝑙𝑢𝑟𝑒) *𝑃𝑐𝑜𝑟𝑟𝑒𝑐𝑡𝑃,𝐶

3. Probability of exposure to material adequately cooked to the correct time-temperature criteria, however post processing there is a segregation failure where non-target susceptible animals (cattle, sheep and goats, and deer) as well as pigs, poultry and farmed fish may be exposed to tissues from the same species. The estimated probability of exposure from this route, R=3 was

𝑃𝑒𝑥𝑝𝑜𝑠𝑢𝑟𝑒𝑃,𝐶,𝑅=(1 − 𝑃𝑟𝑎𝑤) ∗ 𝑃𝑓𝑎𝑖𝑙𝑢𝑟𝑒

4. The collection, processing and on farm system works correctly, in that all material is cooked adequately to the correct time-temperature criteria and all materials are correctly segregated. The estimated probability of exposure to this route, R=4 was

𝑃𝑒𝑥𝑝𝑜𝑠𝑢𝑟𝑒𝑃,𝐶,𝑅 = (1 − 𝑃𝑟𝑎𝑤) ∗ (1 − 𝑃𝑓𝑎𝑖𝑙𝑢𝑟𝑒) ∗ 𝑃𝑐𝑜𝑟𝑟𝑒𝑐𝑡𝑃,𝐶

Model system 2: No species segregation prior to processing Where food waste is not segregated by species for meat products prior to processing, there are a limited number of exposure pathways available:

1. Probability of exposure to raw material due to contamination. As material non-segregated, there is exposure for non-target susceptible animals (cattle, sheep and goats, and deer) as well as pigs, poultry and farmed fish being fed tissues from the same species. The estimated probability of exposure from this route, R=1 was

𝑃𝑒𝑥𝑝𝑜𝑠𝑢𝑟𝑒𝑃,𝐶,𝑅 = 𝑃𝑟𝑎𝑤

2. Probability of exposure to material adequately cooked to the correct time-temperature criteria. As material non-segregated, there is exposure for non-target susceptible animals (cattle, sheep and goats, and deer) as well as pigs, poultry and farmed fish being fed tissues from the same species. The estimated probability of exposure to this route, R=2 was

𝑃𝑒𝑥𝑝𝑜𝑠𝑢𝑟𝑒𝑃,𝐶,𝑅 = (1 − 𝑃𝑟𝑎𝑤)

The probability of cross contamination of streams associated with species segregation failure, 𝑃𝑓𝑎𝑖𝑙𝑢𝑟𝑒, and the probability of cross contamination of cooked processed product with

raw materials, 𝑃𝑟𝑎𝑤, are parameterised in the following sections.

44

7.4.1 Probability of a segregation failure (%)

As previously discussed, a segregation failure may occur at several points in the collection, processing and on farm distribution of feed to the target animals of pigs, poultry and farmed fish. A review of available data to estimate the probability of cross contamination between different segregated feeds, 𝑃𝑓𝑎𝑖𝑙𝑢𝑟𝑒, in current operation in Britain was carried out using

sample data from the National Feed Audit; the review is provided in Appendix 5. If it was assumed that the implementation of the current controls for enforcement of separation would be the same for the separation of source waste food materials for animal feed, then it is likely that there would be a low probability of a breach event occurring each year. From viewing the probability of segregation breaches in bakery waste and with fish meal, the lowest rate of segregation failure occurred with 25 samples of fish bone detected in 54,272 ruminant feed, equating to a probability of 4.6 x10-4 per sample. The maximum estimated probability of segregation failure occurred on farm, with 4.3 breaches identified from 1,352 visits, which is equivalent to a probability of 3.2 x 10-3 breaches per inspection. When summing the total number of breaches and total samples/inspections, the average probability of failure was estimated to be 5.36 x10-4 per sample/inspection. With no further information available, these values were used in the risk assessment with the uncertainty described in the risk assessment using a truncated lognormal distribution.

7.4.2 Probability of cross contamination of cooked materials with raw food waste (%)

There are a number of processes involving foods, pharmaceuticals, fuels and other goods produced in Britain, where raw products must be separated from derivatives. The probability of cross-contamination of raw waste food materials and the cooked product for an industrial sized plant is not considered to be negligible. Section 7.1 details a number of ways in which raw materials could enter the final product including inadequate separation of materials in storage, incorrect use of equipment, carriage by fomites, operatives clothing, footwear and movement by vermin. Whilst there are routes by which contamination may take place, the different visual appearance and smell of raw food waste as compared to processed should prevent large volumes of materials being cross-contaminated. However, small amounts of raw material may enter feed in volumes still capable of causing infection. It is likely that the probability of

such contamination taking place on a per sample basis, 𝑃𝑟𝑎𝑤, is lower than that for segregation failure, however the true value is likely to depend on the exact process employed. It is assumed that the probability is 10% of that estimated for a segregation failure. This results in a very low probability, (is very rare but cannot be excluded). It should be emphasized that this risk assessment does not assess the risk associated with backyard feeding of livestock or the intentional illegal use of food waste in animal feed. Due to the uncertainty associated with this parameter, the impact on the risk estimates has been assessed in the scenario analysis.

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8. CONSEQUENCE OF EXPOSURE TO ORAL DOSE In this risk assessment, the probability of infection is dependent on the probability of the dose causing infection and on the probability of exposure via one of four routes as described in section 7.4.

8.1 Probability of infection per load

A dose response model is used to determine the probability of infection occurring as a result of exposure to a dose of a pathogen. The proportion of a population that becomes infected from a single dose, 𝑃𝑖𝑛𝑓𝑙𝑜𝑎𝑑𝑃,𝐿

, can be estimated by the following exponential dose response

equation (Teunis and Havelaar, 2000; French et al., 2002):

𝑃𝑖𝑛𝑓𝑙𝑜𝑎𝑑𝑃,𝐶,𝑆,𝑇,𝐿= 1 − exp(−𝑟 ∗ 𝐼𝑙𝑜𝑎𝑑𝑃,𝐶,𝑆,𝑇,𝐿) (Equation 1)

Where r is the pathogen infectivity constant. This model assumed that each infectious

particle’s action is independent, that is, the probability of infection by each single agent was independent of the size of the dose. When 𝑃𝑖𝑛𝑓𝑙𝑜𝑎𝑑𝑃,𝐶,𝑆,𝑇,𝐿= 0.5, that is, 50% of an exposed

population becomes infected (ID50) from the dose, -r = Ln(0.5)/1. Substituting into Eq 1:

𝑃𝑖𝑛𝑓𝑙𝑜𝑎𝑑𝑃,𝐶,𝑆,𝑇,𝐿= 1 − exp(𝐿𝑛(0.5) ∗ 𝐼𝑙𝑜𝑎𝑑𝑃,𝐶,𝑆,𝑇,𝐿) (Equation 2)

8.2 Probability of infection per year by exposure route

The probability of infection per year is dependent on (1) the probability of infection per load,

𝑃𝑖𝑛𝑓𝑙𝑜𝑎𝑑𝑃,𝐶,𝑆,𝑇,𝐿, as estimated in section 8.1, (2) the total number of loads per year, 𝑁𝑙𝑜𝑎𝑑𝑠𝑆,𝐿

as estimated in section 7.2, and (3) the probability of exposure given segregation, segregation failure, and cross contamination of cooked food with raw food, 𝑃𝑒𝑥𝑝𝑜𝑠𝑢𝑟𝑒𝑃,𝐶,𝑅

, as

estimated in section 7.4:

𝑃𝑖𝑛𝑓𝑦𝑒𝑎𝑟𝑃,𝐿,𝑇=∑[1 − (1 −∑∑

4

𝑅=1

𝑃𝑖𝑛𝑓𝑙𝑜𝑎𝑑𝑃,𝐶,𝑆,𝑇,𝐿

5

𝐶=1

∗ 𝑃𝑒𝑥𝑝𝑜𝑠𝑢𝑟𝑒𝑃,𝐶,𝑅)𝑁𝑙𝑜𝑎𝑑𝑠𝑆,𝐿]

3

𝑆=1

Where the total probability of infection per year is summed over all C commodity types, R routes of exposure, and S source food waste material to estimate the overall risk estimate for

each pathogen and livestock fed material, for each processing condition.

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Table 7: Summary table of input parameters and functions

Value/distribution Unit Reference

Parameter

Weight of illegally imported, infected meat per year, 𝑁𝑖𝑙𝑙𝑒𝑔𝑎𝑙1

~Lognorm(mean = 263, 5th =

7.55, 95th 794.01) Truncated at 0

kg Hartnett et al., 2004

Weight of illegally imported, infected fish per year, 𝑁𝑖𝑙𝑙𝑒𝑔𝑎𝑙2

=𝑁𝑖𝑙𝑙𝑒𝑔𝑎𝑙1∗37,198

67,657 % Fish and meat seizure

data 01/04/06-31/03/12 (Defra, 2013)

Weight of illegally imported, infected dairy per year, 𝑁𝑖𝑙𝑙𝑒𝑔𝑎𝑙3

=𝑁𝑖𝑙𝑙𝑒𝑔𝑎𝑙1∗(48,934∗(1−0.034))

67,657 % Dairy and meat

seizure data 01/04/06-31/03/12; egg seizures listed under dairy (Defra, 2013; UK Border Agency, 2014)

Weight of illegally imported, infected eggs per year, 𝑁𝑖𝑙𝑙𝑒𝑔𝑎𝑙4

=𝑁𝑖𝑙𝑙𝑒𝑔𝑎𝑙1∗(48,934∗0.034)

67,657 % Dairy and meat

seizure data 01/04/06-31/03/12; non-egg seizures listed under dairy (Defra, 2013; UK Border Agency, 2014)

Weight of infected meat from live animals illegally imported per year, 𝑁𝑖𝑙𝑙𝑒𝑔𝑎𝑙5

=𝑁𝑖𝑙𝑙𝑒𝑔𝑎𝑙1∗ 0.01 % Assumption based on

discussions with Import Officials (2012)

Weight of legally imported, infected products per year, 𝑁𝑙𝑒𝑔𝑎𝑙𝐶

~𝑁𝑖𝑙𝑙𝑒𝑔𝑎𝑙𝐶∗

𝐵𝑒𝑡𝑎𝑝𝑒𝑟𝑡(0.01,0.1, 0.15)

% Assumption

Weight of domestic, infected products per year, 𝑁𝑑𝑜𝑚𝑒𝑠𝑡𝑖𝑐𝐶

~𝑁𝑖𝑙𝑙𝑒𝑔𝑎𝑙𝐶∗

𝐵𝑒𝑡𝑎𝑝𝑒𝑟𝑡(0.001,0.01, 0.015)

% Assumption

Proportion of illegal products disposed in food waste, 𝑃𝑖𝑙𝑙𝑒𝑔𝑎𝑙𝑤𝑎𝑠𝑡𝑒𝑆

~𝐵𝑒𝑡𝑎𝑝𝑒𝑟𝑡(0.05,0.122,0.2 ) *0.075/0.123 (s=1)

*0.023/0.123 (s=2)

*0.025/0.123 (s=3)

% Hartnett et al., 2004

Proportion of legal and domestic products disposed in food waste, 𝑃𝑙𝑒𝑔𝑎𝑙𝑤𝑎𝑠𝑡𝑒𝐶

C=1,5~𝐵𝑒𝑡𝑎𝑝𝑒𝑟𝑡(0.06,0.07,0.08 ) C=2,3,4

~𝐵𝑒𝑡𝑎𝑝𝑒𝑟𝑡(0.08,0.1,0.12 )

% Assumption

47


Parameter

Initial loading of infectivity in product type, 𝐼𝑟𝑎𝑤𝑃,𝐶

Refer to Table 4 ID50/kg

Refer to Appendix 2

Probability of pathogen survival post handling, 𝑃𝑠𝑢𝑟𝑣𝑖𝑣𝑎𝑙𝐶,

~ Uniform (0.03,0.15) % Adapted from Gale, 2002 and Corso, 1997

Conversion of ID50 units into oral doses, 𝐼𝑜𝑟𝑎𝑙𝑃,𝐿

Refer to Table 5 Oral ID50/ID50

Refer to Appendix 3

Total weight of food waste collected per year, 𝑁𝑠𝑜𝑢𝑟𝑐𝑒𝑆

S=1, 4.6 x 109 S=2+3, 3.76 x 109

kg FERA, 2012

Reduction in infectivity from processing of food waste into feed, 𝑅𝑡𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒𝑃,𝐶,𝑇

Refer to Table 6 Log reduction

Refer to Appendix 4

Proportion of food waste being diverted to animal feed, 𝑃𝑓𝑒𝑒𝑑𝐿

,

Where domestic waste included: ~ Pert (1%,5%,7.5%) Where domestic waste excluded: ~ Pert (1%, 11%,17.2%)

% Adapted from historic data (Parliamentary and Health Service Ombudsman, 2007), and assessor’s opinion (max 5% of pig population fed processed waste)

Proportion of feed manufactured into different livestock

sectors, 𝑃𝑝𝑓𝑒𝑒𝑑𝐿

L=1,2,3~

𝐵𝑒𝑡𝑎𝑝𝑒𝑟𝑡 (4.6 x10−4, 5.36 x10−4,

3.2 x10−3)

L=4 ~𝑈𝑛𝑖𝑓𝑜𝑟𝑚(0.75,0.95) L=6,7 ~

(

1 − 𝑃𝑝𝑓𝑒𝑒𝑑1− 𝑃𝑝𝑓𝑒𝑒𝑑2

−𝑃𝑝𝑓𝑒𝑒𝑑3− 𝑃𝑝𝑓𝑒𝑒𝑑42

)

% Adapted from historic data and assessor’s opinion

Daily amount of processed waste consumed by livestock

species, 𝐿𝑜𝑎𝑑𝐿

L=1=point value 8 L=2~Uniform(1.4,2.3) L=3~ Uniform (0.25,1) L=4~ Uniform (8,12) L=5~ Uniform (0.1,0.15) L=6~ Uniform (5 x 10-4, 2.25 x

10-2)

kg FAO, 1997; Perkins, 1991; MLC, 2006; Manitoba, 2002; FAO, 2014

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Parameter

Probability of a segregation failure, 𝑃𝑓𝑎𝑖𝑙𝑢𝑟𝑒

~Lognorm(0.000536,0.00002) Truncated at min 0.000461

% Refer to Appendix 5

Probability of cross contamination of cooked materials with raw food

waste, 𝑃𝑟𝑎𝑤

~0.1*𝑃𝑓𝑎𝑖𝑙𝑢𝑟𝑒 % Assessor’s opinion

Where P refers to pathogen 1 to 16 as listed in the hazard identification

𝐶 refers to Commodity 1 to 5: 1=meat, 2=fish, 3=dairy, 4=eggs, 5= live animals S refers to Source waste material 1 to 3: 1=domestic waste, 2=catering waste, 3=former foods T refers to four temperature processing criteria at 0ºC (raw), 70ºC, 100ºC and 130ºC L refers to the livestock species fed the processed feed, from 1 to 6 representing 1= cattle and camelids, 2=deer, 3=sheep and goats, 4=pigs, 5=poultry, and 6=fish.

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9. RESULTS Uncertainty was considered in the model where possible and is represented by 5th and 95th percentiles (within parentheses), which indicate the range within which 90% of the results lie. The greater the range between the percentiles, the greater the uncertainty. The model was run for 220,000 iterations using Latin Hypercube sampling. Convergence was achieved to 3% of the mean between 200,000 and 220,000 iterations. It should be emphasised the risk assessment is based on a theoretical process and therefore there is considerable uncertainty associated with results that is not quantified in the risk assessment. The risk assessment was quantitatively parameterised. However, for ease of communication, the final results have been provided according to a qualitative scoring: Probability term (EFSA,

2006)

Probability of event per year (EFSA, 2006; OIE, 2004)

If assumed stable (event once every)

Negligible So rare that it does not merit to be considered

<0.1% > 1000 years

Very Low Very rare but cannot be excluded

0.1% to 1% 100 to 1000 years

Low Rare, but does occur 1% to 10% 10 to 100 years Medium Occurs regularly 10% to 66% 1.5 to 10 years High Occurs very often 66% to 90% 1.1 to 1.5 years Very High Events occur almost certainly >90% < 1.1 years

Two case studies were implemented in the model with results provided here:

Implementation of a intra-species barrier – only catering waste originating from restaurants, canteens, fast food premises and former foodstuffs was permitted (domestic catering waste deemed not fit for segregation)

o At three different processing conditions: 70°C for 30 minutes, 100°C for 1 hour, and 130°C for 30 minutes.

Lifting of intra-species barrier (ruminant feed still in place) – all source materials used for industrial production of animal feed.

o At three different processing conditions: 70°C for 30 minutes, 100°C for 1 hour, and 130°C for 30 minutes.

In addition, a sensitivity analysis was conducted together with a scenario analysis investigating the impact on results of several uncertain parameters identified during model development.

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9.1 Estimated weight of infected material entering food waste

The release assessment estimated the weight of infected material entering food waste per year from three different routes deemed to be the most likely for entry of the hazards – the illegal import, legal import, and domestic production of meat, meat products, fish, dairy, eggs and live animals. The weight of material infected with ASF, CSF, FMD and SVD that was imported into GB was estimated previously. The greatest weight was estimated for CSF, and these values were used as a conservative estimate for each of the 16 pathogens identified in the hazard identification. The results by commodity type by source food waste material are provided in Table 8. Table 8: Estimated mean weight (kg) of infected material entering GB waste food that

is collected per year (5th and 95th percentiles) Weight (kg) Meat Fish Dairy Eggs

Domestic kitchen waste

22.0 (2, 68) 12.4 (0.9, 39) 15.8 (0.4, 49) 0.6 (0.04, 1.7)

Commerical catering waste

8.0 (0.6, 25) 4.9 (0.4, 15) 6.2 (0.4, 19) 0.2 (0.02, 0.7)

Former food waste

8.6 (0.6, 26) 5.1 (0.4, 16) 6.5 (0.5, 20) 0.2 (0.02, 0.7)

Total 38.6 (3, 120) 22.4 (2, 70) 28.5 (2, 88) 1 (0.07, 3)

9.2 Results from implementation of an intra-species barrier

The implementation of an intra-species barrier requires a segregation step to ensure that the meat from the same species is not fed to that species. Domestic waste was deemed unsuitable for segregation and therefore, such waste was excluded from this theoretical process with material dervied soley from commerical/industrial source streams. For a model system which includes heating food waste to 70°C for 30 minutes and a degree of by-pass (cross contamination of raw material in final product and failure to correctly segregate), it was estimated that few pathogens would survive to levels sufficient to cause infection. From Table 9 it can be seen that of 16 hazards, only ASF, IPN, FMD, HP-AI, and ND were estimated to cause infection at Medium, Low or Very Low probability per year. When increasing temperatures to 100°C and 130°C, only ASF, IPN, FMD and ND were estimated to have a non-negligible probability of causing infection: ASF was estimated to be inactivated at temperatures of 70°C and above. However, due to the high estimated titre of ASF in infected meat products (between 104.25 and 108 HAD50 per g), combined with relatively low oral dose to initiate infection; the infrequent accidential contamination of cooked product with raw together with segregation failure was estimated to be sufficient to produce a non-negligible probability of infection per year. The probability of infection was estimated to be a mean of Very Low, ranging from Negligible to Very Low when considering uncertainty at the 5th and 95th percentiles. On average the risk equated to 1 in 680 years. IPN is a resistant virus that may survive processing at 70°C, at which temperature it is assumed that there was a mean Medium risk of infection per year which was based on the risk associated with cooked, correctly segregated feed. The segregation step was assumed to be incomplete for the production of fish feed; with only farmed fish being banned from

51

feeding to farmed fish, whilst wild fish may be permitted. It was assumed that the exclusion of farmed fish from feed in the theoretical process reduced the probability of other fish meat entering the feed to 20% but this estimate is associated with unquantified uncertainty. The associated uncertainty ranged between Negligible and High at 70°C. At higher temperatures, the risk reduced to Very Low (equating to once every 360 years) which was based on the risk associated with the accidental contamination of cooked product with raw (wild) fish meat, and varied between Negligible and Low due to uncertainty at the 5th and 95th percentiles.

Table 9: Summary of the mean risk of infection per year from the industrial processing

of catering waste and former foods (domestic excluded) given segregation Common name

Processing criteria for cooked products 70°C for 30 minutes 100°C for 1 hour 130°C for 30 minutes

B. anthracis spores

Negligible Negligible Negligible

Brucella sp.


S. Gallinarum

Negligible

Negligible

Negligible

CWD

Negligible

Negligible

Negligible

HP-PRRS


ASF

Very Low (1/680 years)



IPN

Medium (1/5 years)



HP-PED Negligible

Negligible

Negligible

CSF

Negligible

Negligible

Negligible

AD Negligible

Negligible

Negligible

FMD Low (pigs) (1/63 years)

Negligible (cattle)

Low (pigs) (1/74 years)

Negligible (cattle)


Negligible (cattle)

EBL

Negligible

Negligible

Negligible

HP-AI Very Low (1/100 years)

Negligible

Negligible

ND Low (1/48 years)

Very low (1/120 years)

Very low (1/120 years)

SPP & GTP

Negligible

Negligible

Negligible

SVD Negligible

Negligible

Negligible

Foot and Mouth Disease (FMD) is a multi-species pathogen where infectivity is found in the meat and milk from infected individuals. Therefore, even with correct species segregation of meat products, pigs can become exposed to the pathogen, for example, in contaminated beef or from contaminated dairy products. With a relatively high initial titre and low oral dose, FMD infection was estimated to be of Low risk, equating to an estimated 1 in 63 years when

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a model system operating at 70°C is used. When processed at higher temperatures, the risk was estimated to reduce to a mean of once in 74 years for FMD in pigs, predominantly due to the accidental contamination of raw contaminated beef or sheep meat, and contaminated dairy products in feed that is correctly segregated and fed to pigs. This estimate of an infection was the highest estimated across all 16 pathogens when commercial food waste (commercial catering waste and former foods) was processed into feed including a heating step of 100ºC and 130ºC.When considering uncertainty associated with the estimate, the probability of infection per year ranged between Negligible and Low at the 5th and 95th percentiles.

The estimated Low to Very Low risk for Newcastle disease (ND) was based on: the persistence of these viruses in dried egg products which can be fed to poultry with correct segregation; the relatively low ingestion dose needed to cause infection in poultry; and the estimated high titres found on the outside of egg shells which may cross contaminate with internal contents given poor hygienic food processes. Further information on the probability of dried egg products being contaminated by the external titre on egg shells may lead to a lowering of this risk estimate.

9.3 Results from non-segregation of food waste

As shown in Table 10, the estimated risk of infection increased when considering the non-segregation of waste food with the lifting of the intra-species feeding barrier. This was due to an increased feeding of animals with feed containing the same species. For example, in a system where there was 100% correct segregation there would be zero risk to pigs from processed food waste containing ASF infection, as ASF would only be present in pig meat and meat products which would be removed from feed processing. For a model system including domestic waste, with no segregation, Brucella, S Gallinarum, CWD, AD, EBL, SPP, GTP and SVD posed an estimated Negligible risk under any temperature of processing. A mean Low risk was estimated for Anthrax spores and HP-PRRS in a model system which included a heating step at 70ºC, estimated to vary between Negligible and Medium due to uncertainty at the 5th and 95th percentiles. When processed into feed including a model system with a heating step of 100ºC and 130ºC, this risk reduced to Negligible, even at the 90th percentile. HP-PED was estimated to pose a mean Very Low risk at all processing conditions, varying from Negligible to Very Low at the 5th and 95th percentiles. Despite an estimated low titre of the virus in meat, HP-PED was estimated to have the lowest oral dose of the hazards included in the risk assessment. The mean risk of infection estimated for IPN, CSF and FMD (in pigs) was Low, even at the higher temperatures. When processed into feed including a heating step of 100ºC and 130ºC, the estimated risk of infection per year ranged between Negligible and Low at the 5th and 95th percentiles. The greatest risk of infection was deemed to be from ASF, HP-AI and ND, with a Medium mean risk of infection even at higher temperatures. For HP-AI and ND the risk estimated was based on: the combined infectivity available through multiple product types from infected poultry (meat, eggs and egg products); the increased persistence of these viruses in dried egg products; the relatively low ingestion dose needed to cause infection in poultry;

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and the estimated initial high titres. When considering uncertainty, the risk range estimated for ND was Very Low to Medium at the 5th and 95th percentiles. There was an extremely wide range of uncertainty associated with HP-AI with the estimated risk ranging from Negligible to Very High at the 5th and 95th percentiles. This wide range of uncertainty was due to the uncertain average titre (measured in logs) of the virus expected in meat (102.8 to 108.5 EID50/g) and eggs (101.8 to 105.6 EID50/g) derived from different species of infected poultry. A more precise estimate of the average titre expected in these two commodities via illegal and legal trade would reduce the uncertainty associated with the main output for this hazard. For ASF, the estimated Medium risk of infection was based on the combination of high titres expected in infected meat and a relatively low oral dose to initiate infection when fed to pigs. The pathogen is effectively destroyed at 70ºC, however, the estimated occurrence of infrequent contamination in the model system was sufficiently high to cause infection, on average, once every two years where a species barrier was not present. When considering uncertainty, this value ranged between Negligible and Very High at the 5th and 95th percentiles. This is an extremely wide range of uncertainty associated with the risk posed by ASF and is due to the uncertain average titre (104.25 to 108 HAD50 per g) of the virus expected in meat and edible offals which varies depending on the meat product considered and period in the incubation period when the animal was slaughtered. A more precise estimate of the average ASF titre expected in meat products would reduce the uncertainty associated with the main output for this hazard.

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Table 10: Summary of the mean risk of infection per year from the industrial processing

of catering waste and former foods (domestic included) with no species segregation

Common name

Processing criteria for cooked products 70°C for 30 minutes 100°C for 1 hour 130°C for 30 minutes

B. anthracis spores

Low (pigs) (1/9 yrs)

Low (sheep) (1/19 yrs)

Negligible Negligible

Brucella sp.


S. Gallinarum

Negligible

Negligible

Negligible

CWD

Negligible

Negligible

Negligible

HP-PRRS

Low (1/14 years)

Negligible

Negligible

ASF

Medium (1/2 years)

Medium (1/2 years)

Medium (1/2 years)

IPN

Medium (1/2 years)

Low (1/73 years) Low (1/73 years)

HP-PED Very Low (1/700 years)



CSF

Low (1/60 years)

Low (1/60 years)

Low (1/60 years)

AD Negligible

Negligible

Negligible

FMD Low (pigs) (1/60 years)

Negligible (cattle)


Negligible (cattle)


Negligible (cattle)

EBL

Negligible

Negligible

Negligible

HP-AI Medium (1/3 years)

Medium (1/3 years)

Medium (1/3 years)

ND Medium (1/6 years)

Medium (1/6 years)

Medium (1/6 years)

SPP & GTP

Negligible

Negligible

Negligible

SVD Negligible

Negligible

Negligible

9.3 Key assumptions

The risk estimates presented were dependent on several key assumptions:

The number of potential hazards and product types, via different import pathways, with the time available, necessitated the simplification of the risk assessment with the assumption that the weight of illegally imported infected products was the same as that previously estimated for CSF (Hartnett et al., 2004). For the majority of pathogens this is most likely an overestimate, however, the uncertainty remains that for certain hazards and product types that the range used may not include the true

55

value. Updated research in this area would reduce the uncertainty which was identified in the sensivity analysis as highly impacting the final model results, however, such data may only be valid for a few years.

There is no minimum threshold dose to initiate infection, it was assumed that each infectious particle’s action is independent, that is, the probability of infection by each single agent was independent of the size of the dose. Any infectivity in the food waste was assumed to be homogenously spread.

It was assumed that the required minimum temperature was held for the required time throughout the food mass. This will require that the particle size is reduced to ensure this occurs with all input food waste types.

In the absence of data on the specific dry weight and nutritional value of the food waste and manufacturing processing associated with producing the animal feed in either liquid or dried product, it was assumed that the weight of food waste equalled the weight of feed consumed per day.

Data gaps were identified for specific pathogens. For example, little quantitative information could be found on the initial infectivity in products for Brucella, S. Gallinarum, EBL, SPP and GTP. This may reflect the fact that very low levels are present initially. There were little data on the oral dose associated with CWD and EBL. Conservative estimates were used for CWD using data from another prion disease – BSE. However, the assumptions that the diseases have similar oral doses may be incorrect. Given the use of assumptions for the initial loadings and oral dose for EBL the results for this pathogen may not be reliable.

All input material must be heat treated with controls in place to prevent by-pass of the thermal process of any collected material at every point in the animal feed pathway. Cross contamination is assumed to occur for 1 in 20,000 waste food products.

There is an implementation of the intra-species recycling ban and ban on ruminant proteins, until there is scientific consensus on emerging theoretical prion like diseases, with the prevention of the feeding of terrestrial animals of a given species other than fur animals with processed animal protein derived from the bodies or parts of bodies of animals of the same species. Segregation failure is assumed for 1 in 2,000 waste food products.

9.4 Sensitivity analysis and scenarios

The risk associated with any process will depend on the exact specification and the degree of compliance with controls. The estimated results presented here are associated with considerable uncertainty and are dependent on the degree to which laboratory experiments and current inspection and sampling results within the National Food Audit (as a measure of compliance) can be extrapolated to the theoretical process of feeding pigs, poultry and fish industrially with processed catering and foodwaste. A step-wise regression analysis was performed to identify those uncertain parameters, which are quantified in the model, and which significantly impact on the final results. To investigate areas where the uncertainty may not be fully quantified in the model, scenarios were conducted investigating segregated commercial food waste (commercial catering waste and former foods).

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Scenarios were selected from those identified in the sensitivity analysis as significantly influencing the risk estimates and those that were broadly parameterised through opinion and where there was significant uncertainty: 1) the amount of infected products entering British food waste per year was doubled from a total of 600 kg to 1,200kg, 2) the percentage of food waste diverted to feed product was increased from feeding a mean 11% to 42%, 3) the exposure due to species segregation of food waste for IPN was increased 2 fold, and 4) the probability of mixing between raw and processed product was doubled when compared to the baseline.

9.4.1 Sensitivity analysis

A step-wise regression with pre-screening of inputs based on their precedence in formulas to the response variable was conducted for one of the key outputs for the risk of infection per year from three different hazards: (1) FMD virus in major target species of pigs, (2) IPN virus in farmed fish, and (3) anthrax bacterial spores in non-target sheep. The sensitivity analysis was conducted for model system of the industrial processing of catering waste and former foods (domestic excluded) given segregation at 130ºC. The regression analysis measured how this output varies due to each parameter value selected for that iteration from input distributions. All parameters in the model represented by a range are included in the sensitivity analysis. There were four uncertain parameters distributions strongly associated with the final output for FMD in pigs: (1) Infectivity titre of FMD in milk products (ID50/kg), (2) the amount of infected illegally imported meat (kg), (3) the percentage of commercial waste to animal feed manufacture (%), and (4) the probability of survival of pathogen post handling in food (%). The impact of the uncertainty associated with the infectivity titre of FMD in milk on the final output is considerable. This uncertainty is associated with whether the 28.5 kg of infected milk collected in food waste has been pooled in a silo prior to production of any dairy products, significantly decreasing the titre to levels of approximately 102.2 TCID50/ml or whether the diary product has come directly from an infected animal with titres as high as 106.6 TCID50/ml. Pasteurisation of milk, and any processing of the milk into cheese or dried milk products would be expected to significantly reduce this infectivity titre further. For IPN in farmed fish there were six uncertain parameters strongly associated: (1) infectivity titre of IPN in fish tissues (ID50/kg), (2) the amount of infected illegally imported meat (kg), (3) negatively correlated with the oral dose (Oral ID50/ID50), (4) the percentage of commercial waste to animal feed manufacture (%), (5) proportion of animal feed destined for feeding fish, and (6) the probability of survival of pathogen post handling in commercial food (%). For anthrax spores in sheep: (1) the amount of infected illegally imported meat (kg), (2) the percentage of commercial waste to animal feed manufacture (%),(3) negatively correlated with the oral dose (Oral ID50/ID50), and (4) the probability of survival of pathogen post handling in food (%). The infectivity titre, oral dose and probability of survival of pathogen post handling were parameterised from the literature. The uncertainty associated with each of these parameters may be reduced from further exploratory work including experimental work. However, as can be seen with the parameterisation of the average titre of infectivity of FMD in dairy products, the titre is significantly dependent on a number of factors. The scale of the production may influence titre (collection of milk into a silo diluting infectivity) and the exact processing prior to being disposed of as food waste (for example, unpasteurised milk, pasteurised milk, dried milk, soft cheese, hard cheese). Such factors are likely to vary considerably between

57

products and in the absence of further information, uncertainty ranges have been implemented where available. The amount of illegally imported meat was based on the highest estimate from previous research conducted 10 years ago (Hartnett et al., 2004), and the percentage of commercial waste to animal feed manufacture for this theoretical industry was estimated by the assessor based on historical uptake of swill feeding. The impact of increasing the latter two parameters on the overall results has been investigated in the scenario analysis in the next sections.

9.4.2 Scenario 1: Amount of infected products entering British food waste per year (kg)

The amount of infected products entering British food waste was associated with significant uncertainty, with this parameter identified by the sensitivity analysis as highly impacting the final result. The parameter values used were based on results of a previous risk assessment (Hartnett et al., 2004) rather than more direct experimental data. The 2004 risk assessment was also based on trade volumes and the pattern of global disease more than 10 years previously. To investigate the impact of values for this parameter outside of the uncertain range used in the risk assessment, the average amount from each route (illegal import, legal import and domestically produced) for each product type which could be viably infected (meat and offal, fish, dairy and eggs) was doubled. Table 11: Scenario 1: Risk of infection per year from the industrial processing of

catering waste and former foods (domestic excluded) with species segregation with doubled amount of contaminated food products

Common name Processing criteria for cooked products


B. anthracis spores


Brucella sp. Negligible Negligible Negligible S. Gallinarum Negligible Negligible Negligible CWD Negligible Negligible Negligible HP-PRRS Negligible Negligible Negligible ASF Very Low (1/350 years) Very Low (1/350 years) Very Low (1/350 years) IPN Medium (1/4 years) Very Low (1/180 years) Very Low (1/180 years) HP-PED Negligible Negligible Negligible CSF Negligible Negligible Negligible AD Negligible Negligible Negligible FMD Low (pigs) (1/35 years)

Negligible (cattle) Low (pigs) (1/40 years)


Negligible (cattle) EBL Negligible Negligible Negligible HP-AI Low (1/66 years) Very Low (1/650 years) Very Low (1/650 years) ND Low (1/33 years) Low (1/79 years) Low (1/79 years) SPP & GTP Negligible Negligible Negligible SVD Negligible Negligible Negligible

Shaded cells denote those hazards by processing criteria where there has been a change in the qualitative risk estimate when comparing the baseline to the scenario (in this scenario an increase)

From Table 11, it can be seen that doubling the amount of contaminated food products entering GB does increase the qualitative risk estimate assigned to two pathogens. HP-AI and ND increase from Negligible to Very Low, and Very Low to Low as shown in the Table.

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The highest risk estimated under the baseline scenario at 100ºC and 130ºC is of an infection once in 74 years for FMD in pigs. Doubling the amount of infected products per year, the highest estimate increases to once in 40 years for FMD in pigs. In conclusion, by opting to use the highest weight estimated from previous analyses in illegally imported meat products (estimated for CSF), it is assumed that the baseline values used in the risk assessment are most likely an overestimate for the majority of the hazards. However, the uncertainty remains that for certain hazards and product types the baseline range used may not include the true value. The uncertainty associated with this parameter could be reduced with further research, particularly that associated with FMD, ASF, IPN, HP-AI, and ND.

9.4.3 Scenario 2: Percentage of commercial waste food processed into feed increased

The total market for animal feed industrially processed from food waste is not known at the current time. The demand for such a product if legalised is likely to be heavily dependent on the cost of other animal feed available (FERA, 2012). It was assumed from historical swill feeding that pigs would be the dominant sector with poultry and farmed fish fed at a lower proportion of total feed produced. It was considered that the mean number of pigs fed food waste would equal the same as the upper limit of historic levels at 2.4%, to a maximum of 5% of the British standing pig population. The total amount of catering food waste and former foods (domestic excluded) industrially processed into animal feed with species segregation was increased by 4.2 times with an approximate 10% of the total standing population of pigs fed with the material per year. Results are provided in Table 12. It can be seen from comparing Table 12 and Table 9 that the estimated risk of infection for some pathogens increases with increasing use of commercial food waste as pig feed. For IPN the risk at 100ºC and 130ºC increases from Very Low to Low, for HP-AI the risk increases for each temperature criteria, from Very Low to Low at 70ºC, and from Negligible to Very Low at 100ºC and 130ºC. Finally the risk for ND increases from Very Low to Low at 100ºC and 130ºC. The risk estimate of an infection once in 74 years for FMD in pigs was the highest estimated across all 16 hazards under the baseline scenario with a mean of 10.2% of commercial food waste diverted to processed feed manufacture at 100ºC and 130ºC. At rates of 42.7% (4.2 x baseline) of commercial food waste being processed, the highest risk estimate increases to once in 22 years for FMD. In conclusion, it can be seen that the scale of the industrial processing of food waste is estimated to have an impact on the probability of infection per year for a number of different hazards.

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Table 12: Scenario 2: Risk of infection per year from the industrial processing of catering waste and former foods (domestic excluded) with species segregation with 42.7% of waste food to feed manufacture



B. anthracis spores


Brucella sp. Negligible Negligible Negligible S. Gallinarum Negligible Negligible Negligible CWD Negligible Negligible Negligible HP-PRRS Negligible Negligible Negligible ASF Very Low (1/165 years) Very Low (1/165 years) Very Low (1/165 years) IPN Medium (1/3 years) Low (1/90 years) Low (1/90 years) HP-PED Negligible Negligible Negligible CSF Negligible Negligible Negligible AD Negligible Negligible Negligible FMD Low (pigs) (1/19 years)



Negligible (cattle) EBL Negligible Negligible Negligible HP-AI Low (1/33 years) Very low (1/310 years) Very low (1/310 years) ND Low (1/19 years) Low (1/42 years) Low (1/42 years) SPP & GTP Negligible Negligible Negligible SVD Negligible Negligible Negligible


9.4.4 Scenario 3: Reduction in exposure due to species segregation of food waste (IPN)

Fish cannot be fed on the bodies or parts of farmed fish of the same species under species segregation. With the time available, little information could be found as to the true value of how much infectious fish material would be removed when processing fish feed. For IPNV in fish the reduction in exposure imposed by the species segregation was assumed to be 80%. To investigate the impact of this scenario, the reduction in exposure was reduced to 40%. In the baseline risk assessment, when catering food waste and former foods (domestic excluded) was industrially processed into animal feed with species segregation, the risk from IPN at 70ºC, 100ºC and 130ºC was 1/5 years, 1/360 years and 1/360 years respectively. With a 2 fold increase in exposure (less fish tissue removed from the picking line when manufacturing fish feed), the risk estimate increased to 1/3 years, 1/125 years and 1/125 years, therefore with the same qualitative ranking as the baseline of Medium, Very Low and Very Low risk. In conclusion, for IPN the effectiveness of the species segregation was not known with an assessors opinion of an 80% reduction. By reducing this exposure to 40%, the same qualitative risk estimates was achieved as estimated in the baseline.

9.4.5 Scenario 4: Probability of cross contamination of cooked materials with raw food waste (%)

There are many different routes by which contamination of cooked materials with raw may take place, the different visual appearance and smell of raw food waste as compared to processed should prevent large volumes of materials being cross-contaminated. With no system in place to make more detailed observations, it was assumed that the probability would be lower than that for segregation failure, however the true value is likely to depend

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on the exact process employed. As a baseline estimate the probability was assumed to be 10% of the probability estimated for a segregation failure. In the scenario, this value was doubled to investigate the impact on the final risk estimates.

Table 13: Scenario 4: Risk of infection per year from the industrial processing of

catering waste and former foods (domestic excluded) with species segregation with double the probability of cross contamination



B. anthracis spores


Brucella sp. Negligible Negligible Negligible S. Gallinarum Negligible Negligible Negligible CWD Negligible Negligible Negligible HP-PRRS Negligible Negligible Negligible ASF Very Low (1/343 years) Very Low (1/343 years) Very Low (1/343 years) IPN Medium (1/5 years) Very Low (1/183 years) Very Low (1/183 years) HP-PED Negligible Negligible Negligible CSF Negligible Negligible Negligible AD Negligible Negligible Negligible FMD Low (pigs) (1/37 years)



Negligible (cattle) EBL Negligible Negligible Negligible HP-AI Very Low (1/116 years) Very low (1/644 years) Very low (1/644 years) ND Low (1/45 years) Low (1/79 years) Low (1/79 years) SPP & GTP Negligible Negligible Negligible SVD Negligible Negligible Negligible


From Table 13, it can be seen that doubling the probability of raw contamination in the final feed does increase the qualitative risk estimate assigned to two pathogens. HP-AI and ND increase from Negligible to Very Low, and Very Low to Low as shown in the Table. The highest risk estimated under the baseline scenario at 100ºC and 130ºC is of an infection once in 74 years for FMD in pigs. Doubling the probability of cross contamination, the highest estimate increases to once in 40 years for FMD in pigs. It is interesting to compare the results from scenario 1 and 4 at the higher temperatures, where a doubling in the average input parameter has afforded similar impacts on the risk estimates at higher temperatures. At 100ºC and 130ºC there are few viable pathogens remaining from correct heating of material, the risk estimate is often due to the amount of raw contamination of product. Therefore, doubling the total amount of infectious material or doubling the rate of cross contamination, has provided the same impact on the final risk estimates.

9.5 Comparison of results to other risk assessments

The quantitative approach taken in the risk assessment permits a comparison to be made of the risk estimate presented in this report with previous work in other developed countries. Table 14 provides a comparison of the final risk estimates from this risk assessment as compared to those previously conducted where pigs are fed. It is difficult to directly compare risk assessments as there are differences in the time periods, the specification of the swill feeding, and different countries will be affected by different risks based on the amount of illegally imported infected material. For example, some of the risk assessments have

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considered only the case of illegal swill feeding with little material fed to pigs, whilst others have investigated unprocessed swill or only swill produced from domestic source unsegregated materials. Table 14: Comparison of risk estimates for the mean number of years between

outbreaks in pigs due to the implementation of some form of swill feeding

Country Pathogen Swill scenario

Species barrier S=segregated

U=unsegregated

Processing UP=unproces

sed* C=cooked

Mean probability of infection

per year

Mean years

between outbreaks

Reference

GB ASFV Legal Commercial, S C 100ºC 0.0015 680 This report USA ASFV Legal Domestic, U UP 0.005 200 Corso, 1997 GB ASFV Legal Domestic and

commercial, U C 100ºC 0.500 2 This report

GB CSFV Legal Commercial, S C 100ºC Neg Neg This report Denmark CSFV Illegal

(1%) Restaurant waste, U

C 0.001† 930† Bronsvoort et al., 2008

GB CSFV Legal Domestic and commercial, U

C 100ºC 0.017 60 This report

USA CSFV Legal Domestic, U UP 0.063 16 Corso, 1997 Netherlands CSFV Illegal Imported

material Not

provided 0.1 10 Horst et al.,

1997 Denmark CSFV Illegal

(5%) Restaurant waste, U

UP 0.102† 9.8† Bronsvoort et al., 2008

GB FMDV Legal Commercial, S C 100ºC, 0.013 74 This report GB FMDV Legal Domestic and

commercial, U C 100ºC 0.014 70 This report

USA FMDV Legal Domestic, U UP 0.043 23 Corso, 1997

GB SVDV Legal Commercial, S C 100ºC Neg Neg This report GB SVDV Legal Domestic and

commercial, U C 100ºC Neg Neg This report

USA SVDV Legal Domestic, U UP 0.005 200 Corso, 1997

* Unprocessed – material may have been cooked in the domestic setting, but assumed not to have been further processed for feed † Median values

However, from the table it can be seen that broadly for SVDV, FMDV, and CSFV as the amount of food waste material increases that is fed to pigs (moving from illegal to legal practices) and the manufacture of feed graduates from processed at 100C to unprocessed, the risk estimate increases with a decrease in the estimated mean number of years between outbreaks. The exception is the risk estimates for ASFV where Corso, 1997 found a lower risk for legal feeding of unsegregated, unprocessed domestic waste in the USA than this report for GB for legal feeding of unsegregated cooked domestic and commercial waste. The difference between these risk estimates may reflect the increasing prevalence of ASFV in Africa since Corso, 1997 was published, and, of greater concern for European countries, the spread into Caucasus and Russian Federation areas in recent years.

9.6 Main conclusions from the risk assessment

When considering the segregation of waste food and based on the effectiveness of the current implementation of segregation for other materials, there would be a Negligible risk for the majority of hazards. The greatest estimated risk of infection of Low is associated with the processing of food waste in a model system involving a heating step of 100ºC or 130ºC resulting in one infection of FMD in pigs of every 74 years. When considering uncertainty associated with this estimate, the probability of infection per year ranged between Negligible and Low at the 5th and 95th percentiles.

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When considering the use of processed food waste without any segregation by species, i.e. the feeding of livestock with materials derived from the same species, the estimated risk of infection increases, ranging from a Negligible risk for many of the hazards to one infection every two years for ASF, even for processes including the highest temperatures, due to accidental contamination of the cooked feed with raw ingredients. This estimate for ASF is associated with considerable uncertainty due to the wide range of infectivity titres that have been measured in infected meat and offal (104.25 to 108 HAD50 per gram of infected meat). Key to reducing the risk posed by the feeding of processed food waste to pigs, poultry and farmed fish is maintaining a very low cross contamination rate of the final product with raw input materials and the correct and stringent segregation of materials from all input source materials to the current standards achieved with bakery waste and restricted proteins enforced by sampling and inspections. It should be emphasized that this risk assessment does not assess the risk associated with backyard feeding of livestock or the intentional illegal use of food waste in animal feed. An analysis of risk management measures has been undertaken in order to investigate whether the three source streams identified (domestic kitchen food waste, other catering waste, and former foods) can be segregated to the level currently achieved with bakery waste and restricted proteins. The results from the risk assessment are highly sensitive to the frequency of cross-contamination of raw material with the final product. An evaluation of the safeguards that would be needed when compared to the process flows provided in Figure 4 and 5 to limit the probability of cross-contamination of raw materials in the final processed product has also been conducted. In addition, the next risk management section outlines a process which may be able to achieve adequate separation of animal feed and waste streams and prevent cross contamination to the levels assessed in the risk assessment.

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10. RISK MANAGEMENT Risk management is the process of determining and implementing measures to achieve an acceptable level of risk. In this section of the report critical controls were determined which would limit the probability of cross contamination or by-pass of thermal processing and segregate source materials to the standards required.

10.1 Measures to reduce the risk of cross contamination or by-pass

In this section, we will consider model systems for the following scenarios:

Model System 1 - a system, where the intraspecies recycling ban is operating, no ruminant origin food material can be sourced, separation is required from feed for non-target species and non-target species cannot have access on farm.

Model System 2 - a system, where the intraspecies recycling ban is not operating, all animal origin food material can be sourced, but separation is required from feed for ruminant species and ruminant species cannot have access on farm.

Two end-products will be considered, a dry coarse meal and a liquid / semi solid product. No consideration is being given to the detection of heavy metals, mycotoxins or other biological or chemical hazards, which may render incoming material from waste streams as unsafe.

10.2 Model system 1 – intraspecies recycling ban is in place, no ruminant origin material can be sourced

This model system would be applicable to the waste stream from food manufacturing businesses, retail premises and commercial kitchens, such as restaurants, canteens and fast food outlets, but would not be applicable to a waste stream from domestic kitchens. It is assumed that a consistently separated product into different species of origin (excluding ruminant) from multiple domestic sources, with no additional control mechanisms operating, such as management oversight, training and written protocols that can be used in commercial enterprises, is not achievable. It is also assumed that separation post collection from domestic properties is not achievable, due to the mixing of food products originating from different species. Important controls and critical control points are identified for the process under consideration that may permit adequate separation in order to prevent intraspecies recycling, use of ruminant origin material, prevent feeding to non-target species and to mitigate against the likelihood of by-pass leading to contamination of processed product with raw intake material. Taking into consideration the risks associated with the sourcing of safe products and the effectiveness of the mechanism for controlling other feed manufacturing processes, process flow diagrams are provided which describe a potential system that may be implemented to limit the risk associated with food waste being used as a feedstock. These process flows have been developed based on the effectiveness of segregation systems currently operating in the feed and food industry for the separation of fishmeal used in non-ruminant feed from ruminant feed and ruminant access and the use of bakery and

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confectionary products containing products of animal origin, such as milk products, fat, eggs/ egg products and non-ruminant gelatine from meat, meat products, fish, fish products and shellfish products (see Appendix 5 for more detailed information). Two scenarios have been developed, one based on the production of a dry coarse meal material (achieved by passing the processed product through a commercial drying process) presented in Figure 4. The second considers the production of a liquid/ semi solid product collected post processing and then transported in a tanker directly to farm, shown in Figure 5. Both scenarios require good quality control protocols for raw materials being received at the processing stage. This would include only sourcing from defined suppliers, rigorous scrutiny of supply (document checks/ audit etc.) and clear identification of the raw material entering the chain either through visible discrimination between eligible and ineligible materials or labelling. Similar control processes have been shown to be effective in the supermarket return depots as described in appendix 5. A primary critical control point in this system is the ability of the responsible operator to control the safe sourcing and identification of the raw material entering the process. The requirement to provide a raw material stream of single species origin and in a form that can be readily identifiable at pre-processing checks (picking line) will restrict the options for sourcing and will rule out a domestic catering waste source. A test of the effectiveness of separation is provided by the use of PCR analysis to monitor or negatively release final product, where the PCR test is used to evaluate which species are present. The successful operation of a picking line will also preclude certain products from being used, for example, the presence of sauces could restrict the ability of the picking line operator to identify the species of the product. Of course, if the product was from a single-species specific source i.e. a factory only handling a single species product, or products in identifiable packaging/ wrappers, it could be considered on a case by case basis for inclusion by the processing plant operator who is responsible for the safe sourcing of raw material. A test of the reliability of food products and food product labelling is again provided by the use of PCR analysis to monitor or negatively release final product. This step will also prevent domestic kitchen waste being included as a raw material stream due to the significant difficulty in sorting and identifying eligible products. Permitted materials could include out-of date raw meat/ meat products or partially/ fully cooked meat/meat products, providing they are visibly recognisable. It also could include all of the other food materials currently excluded as catering waste, because they have been present in a kitchen, such as fruit, vegetables, salad crops, bread, and bakery products. The full product list of acceptable materials would need further development, but may include examples, shown in Table 15. Products that are not visually recognisable on a picking line would not be eligible for use. Examples of products which are likely to be able to permit segregation are provided in Table 16.

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Table 15: Food products which may be visually identifiable and may be acceptable to

be processing into animal feed from certain locations

Restaurants & Canteens Fast-food Sandwich shops Roasts Raw fish and uncooked

chips/ potatoes Cooked meats

Kebabs Kebabs Fish Fish & Chips Fried chicken Cheese / eggs

Eggs Fruit Sausage roll Shellfish Bread Tuna mayonnaise fillings

Raw unused meat / fish / shellfish products

Desserts/Puddings Sandwiches containing eligible fillings

Desserts/Puddings Raw unused meat / meat products

Bread

Vegetables, fruit and Salad crops

Cooked fish and chips (depending on risk from other products in fryer).

Salad crops

Bakery goods Bakery goods

Table 16: Food products which may not be visually identifiable, and therefore not permitted into animal feed by location origin

Restaurants & Canteens Fast-food Sandwich shops Stews Pies / Sausages Sandwich fillers (e.g.

coronation chicken) Curries Burgers

Food remnants from a plate or dish

Curry/ Indian food

Products covered in sauces or gravies

Chinese food

Foodstuffs from manufacturing processes that are clearly identifiable either through visible inspection, identifiable packaging/ wrapping or derived from a single species source would be permitted. Safe sourcing of this product would be the responsibility of the processing plant operator and should include appropriate measures to circumvent fraudulent labelling.

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Figure 6: Proposed Workable Scenario (dried product)

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Figure 7: Proposed Workable Scenario (liquid product)

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10.3 Risk management controls and critical control points

Appendix 5 sets out details of the control measures currently in place to control feed materials. These have been on the whole, effectively adopted by the feed industry. As demonstrated in the previous process flow diagrams (Figures 6 and 7), the key control mechanisms can be extrapolated to give a number of key features, which if adopted by responsible operators, would lead to effective separation systems. Measures adopted in the operation of ABP processing plants are also employed, along with consideration of the swill feeding controls before the ban on swill feeding in 2001. These key control features include: a) Safe sourced raw material – It is vital that waste food products are derived from ‘safe’ sources. A quality control system would be needed to effectively control the eligibility of products throughout the production chain. Only products from recognised supply routes e.g. single species food production, and clearly identifiable products (either visibly or through labelling etc.) and supported by traceable documentation back to source should be considered. There must be a means of selecting a meat or meat product, originating from a specific species (and which has not been in contact with meat/ meat products from non-target species), that can be easily identifiable on entry into the processing plant. A list of eligible food types from each type of establishment can be considered, based on likelihood of identification further downstream and potential for contamination with meat/ meat products originating from non-target species. For example, waste food from plates may carry a high risk of mixing of products from several species of origin and a low risk of identification of origin of the species of origin of the meat / meat product, whereas out-of-date ham, still in unopened packaging is likely to carry a low risk of contamination with meat from another species and a high likelihood of identification. Staff must receive appropriate training in the requirement for segregation of products. The data (and experience of APHA) relating to compliance with sourcing of bakery and confectionary products from supermarkets and retail businesses (see Appendix 5) confirms that safe sourcing is unlikely to be totally reliable in removing ineligible feed or other product items from the system. Therefore, a robust critical control point is essential on entry to the processing plant and the reliability of the system requires analysis of final product, either through negative release or continuous monitoring, using a test such as PCR analysis to reliably detect contamination with material originating from non-target species down to a 0.1% contamination level in finished product. b) Separation during transport –a means of collecting the raw material and separating it from other waste streams during collection and transport must be in place, for example, colour-coded bins or colour-coded plastic bags. c) Control of supply chain – The processing plant operator must put in place adequate measures to ensure control of raw material supply. This could be in the form of formal supply contract or audit of the supply chain.

d) Location of processing plant – the processing plant must not be located on a site where farm animals are located, even if there is adequate separation of buildings/ storage of

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raw food materials. This reduces the likelihood of direct feeding of unprocessed food waste or indirect transmission through scavenging wildlife. e) Checking point pre-processing (picking line) – there must be a visual checking point on arrival at the processing plant. A system is needed using conveyor belts and operatives to view all products entering the system to confirm correct starting material is entering the line. Staff must be trained to differentiate between eligible and ineligible products. Protocols must be put in place to deal with ineligible products received for processing – ability to stop the line, remove ineligible product and clean and disinfect contaminated areas. Existing effective systems currently operate for bakery returns from supermarket returns depots. f) De-packaging – risks associated with processing of plastic packaging will require all packaging/ wrapping to be removed prior to processing. De-packaging may need to be completed manually to minimise the risk of any plastic entering the processing chamber. g) Separation during processing – there must be entirely separate storage facilities and plant/ processing equipment for each product line at the processing plant. Clean and dirty areas must be identified and documented protocols controlling flow of raw material and product through the production process. h) Processing Parameters (time/ temperature recording/ particle size) – processing plant operators will need to demonstrate that their process meets the processing requirements described in this document. They must be able to identify process critical control points and have procedures in place to control and monitor particle size, temperature and other critical parameters. i) Prevention of diversion & control of fomites – processing plant operators must take steps to prevent diversion of unprocessed material into processed final product and to control the spread of pathogens through fomites. j) Negative release – a requirement to negatively release final product or audit batches of final product using Polymerase Chain Reaction testing (PCR) to detect low level presence of ineligible DNA would validate effectiveness of separation. A system for disposing of positive product appropriately would be required. k) Separation post processing – there has to be adequate separation post processing during:

Storage at the processing plant;

Transport directly to farm or for blending and use in compound feed;

Manufacturing into compound feed; and

Subsequent storage and transport to farm.

l) An approval requirement for processing plants and an authorisation requirement for feedmills and farms using processed catering waste in feed production and for farms using compound feed containing catering waste, where non-target species or ruminants are kept – this would be in line with current control requirements under the ABP and TSE legislation and enables inspectors to check separation arrangements on a risk basis and to target samples for analysis under the National Feed Audit inspection programme.

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10.4 Model system 2 – intraspecies recycling ban is not in place, all animal origin material can be sourced

This model system would be applicable to all three waste stream scenarios i.e. food manufacturing businesses, retail premises, commercial kitchens, such as restaurants, canteens and fast food outlets and domestic kitchens. The operational system is the same post-processing plant as model system 1, except the only separation requirement post processing is from ruminant feed and ruminant access. None of the separation controls are required pre-processing and no measure is required to establish the effectiveness of separation. The management controls and critical control points remaining from the list for model system 1 include: a) Location of processing plant – the processing plant must not be located on a site where farm animals are located, even if there is adequate separation of buildings/ storage of raw food materials. This reduces the likelihood of direct feeding of unprocessed food waste or indirect transmission through scavenging wildlife. b) Checking point pre-processing (picking line) – a checking point pre-processing in this model is not aimed at ensuring separation, but at detecting ineligible and unsafe materials, other than metals (which could be detected and removed using magnetics). For instance, in collecting surplus bakery products from supermarkets, other products have entered the waste stream, such as glass and flowers. This check also ensures that no rotting or decomposing food waste enters the system. c) De-packaging – risks associated with processing of plastic packaging will require all packaging/ wrapping to be removed prior to processing. De-packaging may need to be completed manually to minimise the risk of any plastic entering the processing chamber. d) Processing Parameters (time/ temperature recording/ particle size) – processing

plant operators will need to demonstrate that their process meets the processing requirements described in this document. They must be able to identify process critical control points and have procedures in place to control and monitor particle size, temperature and other critical parameters.

e) Prevention of diversion & control of fomites – processing plant operators must take steps to prevent diversion of unprocessed material into processed final product and to control the spread of pathogens through fomites. f) Separation post processing – there has to be adequate separation post processing

from feed intended for ruminants and from ruminant access during:

Storage at the processing plant;

Transport directly to farm or for blending and use in compound feed;

Manufacturing into compound feed; and

Subsequent storage and transport to farm. g) An approval requirement for processing plants and an authorisation requirement for feedmills and farms using processed catering waste in feed production and for farms using compound feed containing catering waste, where ruminants are kept – this would be in line with current control requirements under the ABP and TSE legislation

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and enables inspectors to check separation arrangements on a risk basis and to target samples for analysis under the National Feed Audit inspection programme.

10.5 Final product post processing

There are two scenarios for the final product post processing: Scenario 1 - a liquid final-product from the processing plant. This is similar to the historical ‘swill’ product. This type of product is unlikely to be suitable for feed industry requirements for manufacture into compound feed. As it is a ‘wet’ product there is an increased likelihood of post-production bacterial contamination, odour and difficulty in handling. As the product is liquid, it is likely to be handled in fully enclosed systems, using storage tanks, pipework and tankers. The scenario envisages transport direct to farm. A final liquid product exiting the processing equipment or cooker requires no end-stage drying processing and therefore may be more amenable to smaller operators e.g. using farm buildings. Final product is likely to be distributed to a low number of receiving farms. The product is unlikely to be suitable for distribution to poultry farms or aquaculture animals (farmed fish).Compound feed for poultry and fish is usually in pellet or crumb form. The main use is likely to be for feeding to pigs, where similar systems have been historically used and still are used for feeding liquid products, such as whey. Scenario 2 – a dry final product which is in crumb form A dry coarse meal is more likely to be considered by the feed industry for incorporation into compound feed for poultry, fish and pigs. It is likely to be first blended with other materials into a ‘biscuit meal’ type product that could be incorporated into pelleted or crumb feed with other feed materials. The further drying process required using for example a drum drier may discourage processing by smaller operators. The more complex and expensive the equipment required, the more likely it is that only larger operators processing high volumes will be left in the market. As distribution of final product, could be widespread, a break down in controls at any level is more likely to affect a larger percentage of the animal population (refer to Appendix 5).

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10.6 Risk management conclusions

Two model systems have been explored, one requiring incoming source material to be separated into species of origin streams (excluding ruminant) prior to entering the processing plant and the other requiring no separation of incoming source material. In both systems, it is important to minimise contamination of processed product with raw unprocessed material. Separation from other feeds destined for non-target species and access by non-target farm animals will be required for dry coarse meal post processing in both model systems, but this will be limited to ruminant feed and ruminant access for model system 2. For model system 1, the data presented demonstrates the critical risk points associated with a move from the current position where feeding of pigs, poultry and fish certain products of animal origin with waste food is not permitted to a system allowing certain product types to be fed under specified conditions. Initially three food waste steams were considered in the risk assessment, domestic kitchen waste, waste from commercial restaurants (non-plate waste) and products arising from food production in commercial factories Domestic kitchen waste was not considered for inclusion as a waste stream source for Model System 1, due to the fact that it would not be possible to meet the risk control measure to provide reassurance that the supply of raw material came from a single species of origin. The mechanics of providing a domestic kitchen stream would make this impossible due to the range of products entering a domestic kitchen and lack of control over the large number of waste originators involved. It is difficult to directly quantify the risks associated with a relaxation to the catering waste controls in the absence of a system in operation and an understanding of the potential scale of the industry. Information has been presented relating to existing sourcing and separation systems currently used in the feed and food industry and the historical likelihood of a breach event occurring over the last 8 years, to existing TSE and ABP Feed ban controls. This indicates that there is a low probability per sample of a breach event occurring. It has also been important to draw on compliance and control measures associated with feed materials sourced from supermarket stores via supermarket returns depots. In the case of supermarket returns depots, separation of eligible products begins at the supermarket store, where areas of the store from which products can be selected are identified, these are transported in colour-coded clear plastic bags in separate roll cages or boxes from store back to returns depot, where the bags are visually checked and then consigned to a compactor. A further visual and physical check then takes place at the receiving feed business, where bags are opened on a conveyor belt by operatives, who can quickly identify and reject ineligible items and material in contact with it. The operative can stop and clean and disinfect the belt down, before resuming operations. Identification of incoming bags means feedback can be given to the individual supplying supermarket retailer or stores, which are performing badly or on systems that are not functioning effectively. Clearly, control in current systems is heavily reliant on a responsible operator, adopting thorough checking and control systems throughout the distribution chain. In particular, the feed operator must ensure adequate checking of materials entering the feed operation. Feed-back systems are essential in trying to ensure better control of operation higher up the system.

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Giving consideration to the levels of compliance within the feed sector and feed supply chain and drawing on the established mechanisms in place within the feed production industry it has been possible to formulate a system of controls that would be effective in allowing the separation required by the TSE and ABP regulatory framework. Measures, including:

Safe sourcing of raw materials;

Controls during transport;

Responsible control of supply,

Location of the processing plant, being not on the same site or location as farm animals,

A checking point pre-processing (picking line),

Strict separation during processing,

Robust processing;

Prevention of diversion of raw material into finished product & control of fomites;

Negative release to PCR analysis; and

Separation at all stages post processing is described and critical to mitigate risks. A responsible processing plant operator, thoroughly auditing segregation measures at supplying food businesses and the successful operation of a picking line on entry of food waste into the processing plant are key control measures, to preclude ineligible products from being used. Selection of product eligibility is partly driven by the impact of certain product types on the effectiveness of the picking line, for example, products including sauces would need to be omitted due to the masking effect on meat products. Of course, if the product was from a single species specific source i.e. a factory only handling a single species product, or products in identifiable packaging/ wrappers, it could be considered on a case by case basis for inclusion by the processing plant operator, who is ultimately responsible for the safe sourcing of raw material. Sampling of final product and analysing through use of PCR provides a monitor of the effectiveness of the segregation in the supply chain and the critical control point on entry into the processing plant. The major advantage of model system 2 is the sourcing of material, which can enter the system from any of the three waste streams, without any separation requirements at source. There would still be an onus on supplying food businesses and receiving feed businesses (processor) to ensure only safe material enters the system, but providing these responsibilities are met, then all food waste could be used. There would also be no need to test the finished product post-processing for speciation of proteins. This model system would enable a more extensive and local supply network than model system 1 and to a large extent minimises the increased risks inherent in complex requirements for species separation in the supply chain. The advantages and disadvantages of allowing a liquid or a dry final product are discussed. A dry final product provides increased opportunities for use and distribution in the feed chain, but also increased points at which separation failure may occur, with an increasingly complex distribution chain through which to trace product and a larger potential number of exposed animals, if significant breaches occur. A liquid final product limits the use and distribution of final product and may increase the opportunity for smaller scale operators to be involved. It has potential disadvantages associated with the former swill feeding operations in terms of odour and form of final product and the potential for increased welfare issues in pig populations receiving it.

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12. APPENDIX 1: HAZARD IDENTIFICATION Hazard identification of important animal pathogens to determine those that are (i) exotic, (ii) a virus, bacteria or fungi (parasites are excluded), and (iii) are assessed as being capable of non-negligible transmission risk to livestock after entry into food chain in meat and meat products, fish, untreated dairy and unprocessed eggs from infected animals, and subsequently being disposed of as catering waste or former foodstuffs.

Disease OIE* Defra† Host species Product type

Agent Included

Bacteria

Anaplasma marginale (Bovine anaplasmosis)

B - Bovine Meat, cheese

Bacteria No, negligible risk

Never detected in Britain (WAHID, 2014). An obligate intracellular pathogen, transmission is either biologically by competent ticks or mechanically (by transferring of blood from an infected animal via biting flies or use of hypodermic needles on multiple animals) (Howden and Geale, 2010). No reports were identified regarding the transmission of A. marginale in carcases or meat products or dairy products.

Bacillus anthracis (Anthrax)

B B Multiple Meat, cheese

Bacteria Yes, meat and meat products

Last detected in Britain in 2006 (WAHID, 2014). B. anthracis is readily isolated in relatively high numbers from blood or tissues of a recently dead animal that died of the disease (OIE Terrestrial Manual, 2009). The gastrointestinal form is less common than the inhalational but more serious, and can occur in outbreaks resulting from the ingestion of raw or undercooked meat containing viable spores (CFSPH, 2007). AQIS (1999) concluded from a review of the literature that that the bacterium is not known to be transmitted in dairy products.

Brucella abortus (Bovine brucellosis)

B B Bovine Meat, cheese

Bacteria Yes, untreated dairy products

Last detected in Britain 2004 (WAHID, 2014) with current Brucellosis Free Status in Great Britain. Present in unpasteurised dairy products, however predominantly an aerosol risk for slaughtermen, with cooked meat safe for human health (AHVLA, pers. comm. 2014). From a review of the literature, Williams (2003) concluded that meat derived from affected herds was a negligible transmission risk. The degree of persistence in unpasteurized cheese is influenced by the type of fermentation and ripening time. The fermentation time necessary to ensure safety in ripened, fermented cheeses is unknown, but is estimated to be approximately three months. Brucella is reported to persist for weeks in ice cream and months in butter (CFSPH, 2007).

Brucella melitensis (excluding B. ovis), (Caprine and ovine brucellosis)

B B Ovine/Caprine Meat, cheese

Bacteria Yes, untreated dairy products

Never detected in Britain (WAHID, 2014). Present in unpasteurised dairy products. The degree of persistence in unpasteurized cheese is influenced by the type of fermentation and ripening time. The fermentation time necessary to ensure safety in ripened, fermented cheeses in unknown, but is estimated to be approximately three months (CFSPH, 2007). Brucella is reported to persist for weeks in ice cream and months in butter (CFSPH, 2007). Carcases and animal products are not important in the epidemiology of the disease, although cases have occurred of human infection from uncooked meat. From a review of the literature, Williams (2003) concluded that meat derived from affected herds is a negligible risk for animal health.

Brucella ovis (Ovine epididymitis)


Bacteria Yes, meat and meat

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Agent Included

products and untreated dairy products

Never detected in Britain (WAHID, 2014). Important sources of Brucella are infected raw milk, and freshly prepared cheese, cream, and butter produced from unheated milk of infected animals (WHO, 2006). Raw meat and certain meat products may also be sources of infection.

Brucella suis (Porcine brucellosis)

B - Swine Meat Bacteria Yes, meat and meat products

Never detected in Britain (WAHID, 2014). Not reported in Britain 2004-1996 (HandistatII). Introductions of this disease to pigs, dogs and humans have resulted from eating contaminated raw meat, raw bone marrow and raw reindeer meat (AFFA, 2001).

Burkholderia mallei, (Glanders)

B B Equine Meat Bacteria No, negligible transmission

Last detected in Britain in 1928 (WAHID, 2014). Glanders is transmitted by direct invasion of abraded skin; inhalation; and by bacterial invasion of the nasal or oral mucous membranes. Carnivores can become infected from eating contaminated meat. B. mallei is readily spread on fomites including harnesses, grooming tools, and food and water troughs. Although this pathogen is inactivated by heat and sunlight, its survival is prolonged in wet or humid environments (CFSPH, 2007). Although humans can become infected, cattle, swine and chickens are resistant to infection, even after experimental injection (Dembek, 1997).

Campylobacter fetus (Bovine genital campylobacteriosis)


Bacteria No, endemic

Reported in Britain 2006 to 2013 (WAHID, 2014), venereal disease.

Chlamydophila abortus (Enzootic abortion of ewes - ovine chlamydiosis)

B Ovine/Caprine Meat Bacteria No, endemic

Chlamydophila psittaci (Avian chlamydiosis)

B - Avian Meat, eggs


Endemic disease, non-notifiable to Defra. “Trade in poultry meat should not be considered a vehicle for the international transmission of C. psittaci” (Cobb, 2011). Vertical transmission has the potential to introduce chlamydia into biologicals produced in eggs (Andresen and Vanrompay, 2000), inferring raw eggs may transmit disease.

Corynebacterium pseudotuberculosis (Caseous Lymphadenitis)

- B Multiple Meat, cheese


Not notifiable in Britain, it was believed to be absent until a case was reported in 1990, but since then appears to have spread steadily through the sheep and goat population. Primary route of infection is entry via wounds with inhalation and ingestion a more uncommon route. Upon infection, C. pseudotuberculosis spreads throughout the body with lymph nodes and internal organs including the lungs, kidney, and liver infected. The bacterium can survive within purulent material for several months. C. pseudotuberculosis may contaminate meat and milk. From 33 human cases of disease, 8 had an occupation of butcher/abattoir worker and one case consumed raw milk (Bastos et al., 2012).

Coxiella burnetii B Multiple Meat, Bacteria No, endemic

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Agent Included

(Q fever) cheese Reported in Britain 2006-2013 (WAHID, 2014). Non-notifiable to Defra.

Dermatophilus congolensis (Dermatophilosis)



Ehrlichia ruminantium (Heartwater)

B - Multiple Meat, cheese

Bacteria No, negligible transmission

Never detected in Britain (WAHID, 2014). Heartwater occurs only where its Amblyomma tick vectors are present and is an obligate intracellular pathogen. Of 6,000 ticks identified in the UK since 2005 by HPA, only one was identified as Amblyomma spp (HPA, 2014). The heartwater organism is extremely fragile and cannot persist outside of a host for more than a few hours. Because of its fragility, the organism must be stored in dry ice or liquid nitrogen to preserve its infectivity (OIE Technical Disease Card). No reports were identified regarding the persistence of Heartwater in carcases or meat products or dairy products.

Leptospira (Leptospirosis) B Multiple Meat, cheese


Reported in Britain 2006-2011 (WAHID, 2014). Leptospires are delicate organisms destroyed rapidly by heating, drying or extremes of pH. However, it is possible that infection may occasionally be spread to carnivores in slaughter scraps from the urinary system, particularly kidneys (MacDiarmid, 1999). Mycobacterium avium Subsp avium (Avian tuberculosis)



Reported in Britain 2004-1996 (HandistatII). Infected meat and faeces have been implicated in transmission to dogs (AHVLA, Ayling, pers. comm. 2014).

Mycobacterium avium Subsp paratuberculosis (Paratuberculosis)

B - Multiple Meat, cheese


Reported in Britain 2006-2013 (WAHID, 2014).

Mycobacterium bovis (Bovine tuberculosis)

B A Bovine Meat, cheese


Mycoplasma agalactiae (Contagious agalactia)



Never detected in Britain (WAHID, 2014). Infected animals shed organisms in urine, feces, nasal and ocular discharges, and secretions including milk (CFSPH, 2009). No reports were identified regarding the persistence of M. agalactiae in carcases or meat products. Woodhead and Morgan (1993), commenting on the risk of introduction of contagious agalactia to the UK, stated that heat treated milk would be unlikely to contain mycoplasmas. They considered that any processing methods, for example, for yoghurt and cheese production would kill any mycoplasmas present.

Mycoplasma capricolum (Contagious caprine pleuropneumonia)

B - Ovine/Caprine Meat, cheese


Never detected in Britain (WAHID, 2014). Disease is transmitted via direct contact. Meat transmission not considered important route of infection (AHVLA, pers. comm. 2014). Inactivated within 60 minutes at 56°C and within 2 minutes at 60°C, but can survive more than 10 years in frozen, infected pleural fluid (OIE Technical Disease Card). Very fragile and not able to exist long in the external environment (OIE Technical Disease Card). AQIS, 1999 concluded that a number of mycoplasmas closely related to the

93


Agent Included

causal agent have been isolated from the milk of goats. However, there was no evidence of transmission via milk (AQIS, 1999a).

Mycoplasma gallisepticum (Avian mycoplasmosis)



Endemic disease, common in backyard poultry. Fresh or frozen poultry meat products produced for human consumption are not ordinarily considered risks for M. gallisepticum infection (Cobb, 2011), however products containing upper respiratory tract material, reproductive tract tissues, and abdominal viscera have been identified as a potential hazard in carcases (MAF, 2013b).

Mycoplasma mycoides (Contagious bovine pleuropneumonia)

A B Bovine Meat, cheese


Last detected in Britain in 1898 (WAHID, 2014). Disease is transmitted via direct contact. Meat transmission not considered an important route of infection (AHVLA, pers. comm. 2014). From a review of the literature, Williams (2003) concluded that carcases and animal products pose a negligible risk of transmission. AQIS (1999) concluded that milk does not play a part in the spread of M. mycoides and that deliberate transmission to cattle by the oral route was not successful.

Pasteurella multocida (Fowl cholera)



Reported in Britain 2008, 2009, 2010, and 2011 (WAHID, 2014). Transmission of P. multocida usually occurs through contact with secretions from the mouth, nose, and conjunctiva of diseased birds (MAF, 2008). Cobb (2011) reviewed the literature and found that whilst the organism had been isolated from the blood of infected chickens and could remain viable for two months at 5°C to 10°C, the organism was fragile, easily inactivated by sunlight, drying, or heat. Cobb, concluded that poultry products are not considered to present a major risk of infection transmission, due to the delicate nature of P. multocida (Cobb, 2011). The organism is inactivated in 15 minutes at 56°C or 10 minutes at 60°C. There is no evidence of transmission within eggs (Glisson, et al., 2003 cited by MAF, 2008). Experimental attempts to infect birds through the oesophagus, proventriculus and crop have failed (MacDiarmid, 1999). Given the fragile nature of the agent to any processing and lack of evidence of transmission via the oral route it is assumed that there is a negligible risk from food waste.

Pasteurella multocida (Haemorrhagic septicaemia)



Never detected in Britain (WAHID, 2014). AQIS, 1999a concluded that the organism was not considered to be a quarantine hazard in dairy products. The pathogen does not survive long enough outside the animal to become a significant source of infection. Williams (2003) assessed carcases and animal products from infected animals as a negligible transmission risk.

Salmonella Abortusovis (Salmonellosis)



Reported in limited zones in Britain 2012-2013 (WAHID, 2014), free between 2004 and 1984 (HandistatII). S. Abortusovis is almost always introduced into a flock by an infected sheep; unlike other Salmonella species, spread by feed, water, other mammals, or birds is negligible (CFSPH, 2005). AQIS (1999) considered S. Abortusovis as not representing a quarantine hazard for dairy products. From a review of the literature, MacDiarmid and Thompson (1997) concluded that it was highly improbable that S. Abortusovis would be introduced into a country via meat or meat products. ”While most foodstuffs may serve as a vehicle for those salmonellae which are not highly adapted to a particular host, S. Abortusovis is not a food-borne pathogen” (MacDiarmid and Thompson, 1997).

Salmonella Gallinarum, B - Avian Meat, Bacteria Yes, meat

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Agent Included

(Fowl typhoid) eggs and meat products and unprocessed eggs

Reported in Britain 2007 and 2012 (WAHID, 2014). Not Reported in Britain between 2004 and 1986 (HandistatII). Horizontal and vertical transmissions are both important in the epidemiology of fowl typhoid. Birds can become chronic carriers of the organism, passing them to their offspring in eggs. Horizontal transmission occurs via the respiratory and oral routes. Birds can ingest bacteria after environmental contamination or during cannibalism (CFSPH, 2009).

Salmonella Gallinarum-biovar Pullorum (Pullorum disease)



Reported 2009, 2010, 2011, 2012 and 2013 (WAHID, 2014). Chicken meat contamination has been described from environments with poor hygiene practices. Poultry meat from birds from licensed abattoirs and processing plants unlikely to act as a vehicle for the spread of S. Gallinarum-Pullorum (Cobb, 2011).

Taylorella equigenitalis (Contagious equine metritis)

B A Equine Meat Bacteria No, negligible transmission

Last detected in Britain in 2012 (WAHID, 2014). Disease transmitted by venereal means. No evidence of transmission via meat or dairy products. There is no evidence that T. equigenitalis survives long-term in a free-living form in the environment (CFSPH, 2009).

Fungi

Histoplasma capsulatum (Epizootic lymphangitis)

B B Equine Meat Fungus No, negligible transmission

Last detected in Britain in 1906 (WAHID, 2014). Transmission is by contact of infected material with traumatised skin, by biting flies, ticks or inhalation. Unlikely to be spread through infected meat and ingestion. Organisms in the soil may survive for long periods. (CFSPH, 2009)

Parasites

Bovine babesiosis, Babesia,


Protozoan No, parasite

Bovine cysticercosis B - Bovine Meat, cheese

Tapeworm No, parasite

Dourine B B Equine Meat Protozoan No, parasite

Echinococcosis/hydatidosis B Multiple Meat Tapeworm No, parasite

Equine piroplasmosis B - Equine Meat Protozoan No, parasite

Horse mange B - Equine Meat Parasite No, parasite

Leishmaniosis B Multiple Meat, cheese


New world screwworm (Cochliomyia hominivorax)

B Multiple Meat Parasite No, parasite

Old world screwworm (Chrysomya bezziana)

B Multiple Meat Parasite No, parasite

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Agent Included

Porcine cysticercosis B - Swine Meat Tapeworm No, parasite

Sheep scab - - Ovine/Caprine Meat, cheese

Parasite No, parasite

Surra (Trypanosoma evansi)

B - Equine Meat Protozoan No, parasite

Theileriosis B - Bovine Meat, cheese


Trichinellosis B - Multiple Meat, cheese

Parasite No, parasite

Trichomonosis B - Bovine Meat, cheese


Trypanosomosis (tsetse-transmitted)



Prions

Bovine spongiform encephalopathy

B A Bovine Meat, cheese

Prion protein

No, endemic

Cases still occurring in 2013 (WAHID, 2014), therefore classed as endemic.

Chronic Wasting Disease - - Cervid Meat Prion protein

Yes, meat and meat products

CWD prions have been found in muscle (meat), as well as other tissues of cervids (CFSPH, 2008).

Scrapie B B Ovine/Caprine Meat, cheese

Prion protein

No, endemic

Viruses

Asfarviridae Asfivirus (African swine fever)

A A Swine Meat Virus Yes, meat and meat products

Never detected in Britain (WAHID, 2014). ASFV is predominantly transmitted by the soft tick Ornithodoros moubata. The virus is found in body fluids and tissues of infected domestic pigs. Pigs usually become infected by direct contact with infected pigs or by ingestion of waste food containing unprocessed infected pig meat or pig meat products. Some processing procedures do not inactivate ASFV (OIE Technical Disease Card).

Arterviridae, Arterivirus (Equine viral arteritis)

B A Equine Meat Virus No, negligible transmission

Reported in Britain 2010, 2011, and 2012 (WAHID, 2014). Present 2004-1996 (HandistatII). A venereal disease, with EAV found in respiratory droplets, semen, urine and faeces during the acute stage, and occurs in the male reproductive tracts, vaginal and uterine secretions, as well as in the ovary and oviduct (CFSPH, 2009). EAV is inactivated in 20–30 minutes at 56-58ºC (133-136ºF) (CFSPH, 2009). No reports were identified regarding the persistence of EAV in carcases or meat products.

Arteriviridae, Arterivirus (Highly pathogenic - Porcine reproductive and respiratory syndrome)

B Swine Meat Virus Yes, meat and meat products

Typical PRRS is a non-notifiable disease of pigs endemic in Britain, first identified in the 1990s. HP-PRRS

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Agent Included

is caused by a variant strain of the type-2 PRRS virus and is currently not present in the UK. First detected in 2006, HP-PRRS has been detected in China and South-East Asia. Previous risk assessments have concluded that there is a negligible risk of introducing HP-PRRS into the UK via the legal import of live pigs or pig meat as no trade is permitted with countries affected (Defra, 2009a). AFFA (2001) completed a review of the literature for meat transmission of PRRS. Several authors suggested that low levels of PRRS virus detected in muscle were due to residual infected blood, not because the muscle cells were actively infected with the virus, and that at temperatures higher than 4°C there was increasing inactivation of the virus. For example, 4°C for at least 1 month, viability reduced by 50% after storage at 37°C for 12 hours, 93% of infectivity was lost after storage at 25°C, complete inactivation within 48 hours at 37°C and 45 minutes at 56°C. AFFA concluded that PRRS virus has been recovered only occasionally from commercial pork, and levels of virus, when present, are low. However, with a specific experimental design, pigs were subsequently infected from the direct feeding of frozen pig meat from infected animals (AFFA, 2001).

Atrophic rhinitis of swine B - Swine - Multi-factorial

No

Not included as several viruses identified in causing syndrome.

Birnaviridae, Avibirnavirus (Infectious bursal disease)


Virus No, endemic

Reported in Britain 2006-2013 (WAHID, 2014). From a review of the literature, Cobb suggests that IBDV-1 should not be considered as a hazard likely to be associated with turkey or duck meat, although trade in chicken meat should be considered a potential vehicle for the spread of IBDV-1 (Cobb, 2011). MAF, 2008, found that there was no evidence that IBDV is carried within the egg, although it is likely that virus may be present on the surface of the shell as transmission of the disease is via the faecal-oral route (MAF, 2008).

Bunyaviridae, Nairovirus (Crimean Congo haemorrhagic fever)

Notifiable - Multiple Meat, cheese

Virus No, negligible transmission

Never detected in Britain (WAHID, 2014). Meat itself is not the source of infection, because the virus is inactivated by post-slaughter acidification of the tissue (ECDC, 2010). Unpasteurised milk has been identified as a route of transmission (Appannanavar and Mishra, 2011) , however, given the virus is inactivated by pH of 6 (meat tissues post rigor mortis), the pathogen unlikely to survive storage or any processing of raw milk.

Bunyaviridae, Nairovirus (Nairobi sheep disease)



Never detected in Britain (WAHID, 2014). NSDV is spread by a tick vector and is relatively unstable. It is a fragile virus outside its narrow optimal pH range (7.4-8.0), and is likely to be inactivated by the pH changes associated with rigor mortis in meat, or processing of dairy products. Carcases and animal products present a negligible disease risk and no special precautions for disposal are warranted (Williams, 2003).

Bunyaviridae, Phlebovirus (Rift Valley fever)

A B Multiple Meat, cheese

Virus No, negligible risk

Never detected in Britain (WAHID, 2014). There are reports of humans, such as abattoir workers, becoming infected with RVF after contact with infected tissues, however no outbreaks in urban consumers. Generally considered that meat from RVF-infected animals is not a source of transmission, as the pH changes associated with rigor mortis inactivate the virus (Williams, 2003). RVFV is stable between pH 7-9 but rapidly inactivated below pH 6.8. AQIS (1999) considered RVF as not representing a quarantine hazard for dairy products.

97


Agent Included

Coronaviridae, Alphacoronavirus (Highly pathogenic - Porcine epidemic diarrhoea)

- - Swine Meat Virus Yes, meat and meat products

The highly pathogenic strain of PED was identified in China in 2010, USA in 2013 and Canada in 2014 and causes high mortality in piglets. PED in a less virulent form is likely to be present in the UK. The main route of transmission is the faecal-oral route, however international trade of pig blood plasma products has been suggested as a mechanism to introduce the disease into a new country. In the Canadian outbreak testing has determined that PED virus was present in samples of US-origin plasma and using swine

bioassay has determined that the plasma ingredient contains PED virus capable of causing disease in pigs. Further testing is required before confirming a direct link with pig feed ingredients and the spread of disease (CFIA, 2014).

Coronaviridae, Coronavirus (Transmissible gastroenteritis)

B - Swine Meat Virus No, largely immune population

Last detected in Britain in 1999 (WAHID, 2014). Oral transmission of TGE by the feeding of muscle and lymph nodes from infected animals to pigs has been demonstrated (Cook et al., 1991). Transmissible gastroenteritis virus has been found to be stable when frozen at -20°C and can withstand a pH as low as 3, however TGE is heat liable being rapidly inactivated at temperatures above 37°C (AFFA, 2001). TGE virus appears to have mutated to the highly infectious but weakly pathogenic Porcine Respiratory Corona Virus (PRCV), which has largely immunized the national herd to TGE (AHVLA, pers. comm. 2013). It is assumed that the transmission of TGE may not be negligible from the import of meat and meat products, however, given that the pig population is largely immune and another coronavirus (Highly Pathogenic Porcine Epidemic Diarrhoea) is included in the risk assessment, TGE is not considered further.

Coronaviridae, Gammacoronavirus (Avian infectious bronchitis)


Virus No, endemic

Endemic disease, common in backyard poultry. From a review of the literature, Cobb (2011) concluded it would be difficult to justify imposing sanitary measures against IBV on any chicken meat products that exclude respiratory or renal tissues (Cobb, 2011).

Flaviviridae, Flavivirus (Japanese encephalitis)

B Equine Meat Virus No, negligible transmission

Never detected in Britain (WAHID, 2014). Japanese encephalitis virus is extremely fragile, and does not survive outside the host for more than a few hours. Carcases and animal products present a negligible transmission risk and no special precautions for disposal are warranted (Williams, 2003).

Flaviviridae, Flavivirus (West Nile fever)

Notifiable B Multiple Meat, cheese,

eggs


Never detected in Britain (WAHID, 2014). WNV is a vector borne disease and is not transmitted to humans through consuming infected birds or animals (CDC, 2014). Rare cases of transplacental transmission and probable transmission in human breast milk have also been reported. Carnivorous mammals and reptiles (e.g., cats and alligators) can be infected by eating contaminated tissues (CFSPH, 2013; Miller et al., 2003). Raptors and crows may become infected when they eat other animals, and insectivorous species might eat infected mosquitoes (CFSPH, 2013). WNV also occurs in the skin of geese and the blood-feather pulp of crows, possibly contributing to transmission by cannibalism and feather picking. However, the oral route is not thought to be a significant form of transmission: experimental oral inoculation with high titres of live virus resulted in transmission in some bird species

98


Agent Included

(Komar et al., 2003, but not chickens (Langevin et al., 2001). There was no evidence in the literature of oral transmission to pigs or ruminants or transmission of disease via eggs. The virus is heat and UV sensitive and completely inactivated at 55-56C for 30 minutes (Fang et al., 2009; Monath & Heinz, 1996; Smithburn et al., 1940). The virus is completely inactivated in 25% solution of human albumin (blood protein) after 30 minutes at 58C (Kreil et al., 2003), WNV loses 50% of infectivity after 10 minutes at 50C (Monath & Heinz, 1996). Loss of infectivity occurs more slowly at 37C (Westaway et al., 1985). Article 8.16.2 of the OIE Terrestrial Code states that members should not impose trade restrictions for WNV on fresh meat and meat products of poultry, regardless of the WNV status of the exporting country

Flaviviridae, Pestivirus (Classical swine fever)

A A Swine Meat Virus Yes, meat and meat products

Last detected in Britain in 2000 (WAHID, 2014). CSFV has acknowledged persistence in meat and meat products and is associated with outbreaks of the disease resulting from waste food feeding. CSFV can remain infectious for nearly three months in refrigerated meat and for more than four years in frozen meat (CFSPH, 2009).

Herpesviridae, Alphaherpesvirinae-Iltovirus (Avian infectious laryngotracheitis)


Virus No, endemic

Endemic disease, common in backyard poultry. Provided poultry meat was not contaminated with respiratory tissues, Cobb (2011) concluded that the spread of ILTV through international trade should be considered unlikely.

Herpesviridae, Alphaherpesvirinae-Varicellovirus (Equine rhinopneumonitis)

B - Equine Meat Virus No, endemic


Herpesviridae, Alphaherpesvirinae-Varicellovirus (Infectious bovine rhinotracheitis/ infectious pustular vulvovaginitis)


Virus No, endemic


Herpesviridae, Macavirus (Malignant catarrhal fever)

B Bovine/cervids Meat, cheese

Virus No, endemic

Reported as present 1996-2004 (HandistatII, 2014).

Herpesviridae, Mardivirus (Duck virus enteritis)


Virus No, endemic

Endemic: seen mainly between April and June each year in Britain– DVE associated with migratory birds (AHVLA, surveillance reports). Disease transmitted by direct contact with infected birds or an infected environment. There is no treatment with prevention relying on vaccination.

Herpesviridae, Mardivirus (Marek's disease)


Virus No, endemic

Reported in Britain 2006-2011 (WAHID, 2014). Common endemic disease of backyard poultry in the UK. The virus is unlikely to be present in meat (Cobb, 2011). Transmission of Marek’s disease virus within the

http://en.wikipedia.org/wiki/Alphaherpesvirinae

http://en.wikipedia.org/wiki/Alphaherpesvirinae

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Agent Included

egg does not occur (MAF, 2008).

Herpesviridae, Varicellovirus (Aujeszky's disease)

B B Multiple Meat Virus Yes, meat and meat products

Last detected in Britain in 2009 (WAHID, 2014). Some conflicting evidence found in the literature regarding stability in the environment. AD is rapidly inactivated when removed from a living host and warmed from 4-13°C, regardless of pH. Alternatively, it has been shown that AD virus retains infectivity in straw, feeding troughs and other fomites for more than ten days at 24°C (AFFA, 2001). Cases of the disease in bears, dogs, cats, farmed mink and ferrets, and wild rats have been attributed to the consumption of meat derived from infected swine which may have included offal (AFFA, 2001).

Orthomyxoviridae, Influenzavirus A (Equine influenza)

B - Equine Meat Virus No, endemic


Orthomyxoviridae, Influenzavirus A (Highly pathogenic avian influenza)

A A Avian Meat, eggs

Virus Yes, meat and meat products and unprocessed eggs

Last detected in Britain in 2008 (WAHID, 2014). HPAI is highly contagious. From a review of the literature, Cobb concluded that the potential for HPAI virus to be present in meat from infected chickens was high (Cobb, 2011). Swayne and Suarez (2000) note, with regard to the risk of importing HPAI in meat products, that “HPAI is a systemic disease and the virus can be present in most tissues, including meat”. HPAI is an identified hazard in eggs with a number of minimum processing requirements for international trade (OIE, 2011). For example, whole eggs at 60ºC held for 188 seconds should inactivate HPAI virus present.

Paramyxoviridae, Avulavirus (Newcastle disease)

A A Avian Meat, eggs

Virus Yes, meat and meat products and unprocessed eggs

Last Reported in Britain in 1997 (WAHID, 2014). Birds slaughtered for meat during disease episodes may be an important source of virus. From a review of the literature, Cobb concluded that poultry meat is a suitable vehicle for the spread of NDV and that poultry, especially in backyard or hobby flocks, can be infected by the ingestion of uncooked contaminated meat scraps (Cobb, 2011). Egg-associated transmission of highly virulent isolates is possible but uncommon, as the embryo usually dies unless the viral titer in the egg is low. Other sources of virus for newly hatched chicks are feces-contaminated eggshells and cracked or broken eggs (CFSPH, 2008).

Paramyxoviridae, Avulavirus (Paramyxovirus of pigeons)

- B Pigeons Meat Virus No, endemic

Paramyxoviridae, Morbillivirus (Peste des petits ruminants)

A B Ovine/Caprine Meat, cheese


Never detected in Britain (WAHID, 2014). Little information available of virus presence in meat. It is

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Agent Included

reasonable to assume that PPRV would be inactivated by the decline in pH accompanying rigor mortis (Williams, 2003). The virus does not survive for a long time outside the body of a host animal (OIE Technical Disease Card). The virus is present in milk, but in a literature review conducted by DAFF, milk was not identified as a likely means of transmission of the virus (AFFA, 2001). PPR virus is sensitive to low pH with stability between pH 5.8 and 9.5 and is very heat sensitive, for example, for another Paramyxoviridae, Rinderpest has a half-life of 5 minutes in cattle blood, spleen or lymph node at 56°C.

Paramyxoviridae, Morbillivirus (Rinderpest)


Virus No, eradicated?

Last detected in Britain in 1877 (WAHID, 2014). Transmission was through direct contact with infected animals as the virus does not survive long outside the host (AFFA, 2001). The last confirmed case of rinderpest was diagnosed in 2001.

Picornaviridae, Aphthovirus (Foot and mouth disease)

A A Multiple Meat, cheese

Virus Yes, meat and meat products and untreated dairy products

Last detected in Britain in 2007 (WAHID, 2014). Transmission of FMDV includes direct contact with infected animals, through contaminated fomites, from consumption of untreated contaminated meat products (waste food feeding), ingestion of contaminated milk, and inhalation of infectious aerosols (OIE Technical Disease Card). FMDV is usually introduced into a country in contaminated feed or infected animals. Waste food fed to swine is a particular concern. This virus can persist in meat and other animal products when the pH remains above 6.0, but it is inactivated by acidification of muscles during rigor mortis. It can survive for long periods in chilled or frozen lymph nodes or bone marrow. Low-temperature pasteurization of infected milk at 72°C for 15 seconds does not inactivate FMDV. High temperature short time (HTST) pasteurization greatly reduces the amount of viable FMDV in milk, but some studies suggest that residual virus may sometimes persist (CFSPH, 2007).

Picornaviridae, Enterovirus (Duck virus hepatitis)


Virus No, endemic

Endemic, Reported in Britain 2007, 2008, 2010, 2011 (WAHID, 2014). Cobb concluded from the available evidence, the transmission of DVH in duck meat should be considered unlikely (Cobb, 2011). There is no evidence to suggest transmission of DVH in eggs (Woolcock 2003 cited by MAF, 2008).

Picornaviridae, Enterovirus (Swine vesicular disease)

A B Swine Meat Virus Yes, meat and meat products

Last detected in Britain in 1982 (WAHID, 2014). SVDV is stable in the pH range 2.5–12.0 and is resistant to fermentation of meats and smoking processes. May remain in hams for 180 days, dried sausages for >1 year, and in processed intestinal casings for >2 years. Transmission includes lesions in skin and mucosa, ingestion and inhalation, oral-faecal route, and waste food being fed to pigs. SVDV not inactivated by normal pH change associated with rigor mortis (OIE Technical Disease Card).

Picornaviridae, Teschovirus (Enterovirus encephalomyelitis)

B - Swine Meat Virus No, eradicated?

Until now in Europe, rules for control Teschen disease were included in the provisions of Council Directive 92/119. However, EU Directive 2002/60 removed the controls, because no outbreaks of this disease have been recorded world-wide for a number of years and the disease risk of removing controls is believed to be minimal (Defra, 2009b)

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Agent Included

Poxviridae, Avipoxvirus (Fowl pox)


Virus No, endemic

Reported in Britain 2004-1996 (HandistatII).

Poxviridae, Capripoxvirus (Lumpy skin disease)



Never detected in Britain (WAHID, 2014). LSDV is thought to be transmitted primarily by biting insects (CFSPH, 2008). No evidence was found for the persistence of the virus in the meat or meat products of infected animals (AQIS, 1999b). Milk is identified as a source of virus (OIE Technical Disease Card), however no evidence of transmission to calves from feeding on milk. LSDV also occurs in cutaneous lesions where it is very resistant to inactivation, surviving in desiccated crusts on the hide for up to 35 days. No reports identified of illegal meat imports seized at British ports of red meat with hide attached (AHVLA, pers. comm. 2014), although information is limited. Hide is removed from British produced animals at abattoir.

Poxviridae, Orthopoxvirus (Horse pox)

B - Equine Meat Virus No, eradicated?

Never detected in Britain (WAHID, 2014).Classical horsepox is considered to occur only in Europe (Mair and Scott, 2009), but has not been reported in Europe for several decades (Bourne, 2012).

Poxviridae, Parapoxvirus (Sheep pox and goat pox)

A B Ovine/Caprine Meat, cheese

Virus Yes, untreated dairy products

Last detected in Britain in 1866 (WAHID, 2014). Capripox viruses are reported to be acid labile and stable over a pH range of 6.6-8.6, therefore the pH changes associated with rigor mortis would be likely to inactivate the virus (Williams, 2003). AQIS (1999) states that the low pH during cheese maturation could not be relied upon for inactivation. However, it has not been possible to infect animals experimentally by the oral route (MacDiarmid and Thompson, 1997).

Reoviridae, Orbivirus (African horse sickness)

A A Equine Meat Virus No, negligible transmission

Never detected in Britain (WAHID, 2014). Dogs have been reported as infected after eating meat from horses infected with AHS virus. However, the role of dogs in the epidemiology of AHS is of questionable significance. At pH values that would usually accompanying rigor mortis, the virus of AHS is inactivated quickly. It is also inactivated by temperatures greater than 60°C (MacDiarmid, 1999). From a review of the literature, Williams (2003) concluded animal products pose a negligible transmission risk with no special disposal methods required.

Reoviridae, Orbivirus (Bluetongue)

A A Multiple Meat, cheese


Last detected in Britain in 2008 (WAHID, 2014). There is no risk of disease spread through milk or meat (EC, 2008). BTV is an enveloped virus and therefore less resistant to heat processes. No reports were identified regarding the persistence of BTV in carcases or meat products. No reports were uncovered of BTV being shed in milk. At pH values that would usually accompanying rigor mortis and cheese maturation, the acid lability of BTV would suggest inactivation of the virus. AQIS (1999) determined that bluetongue “is unable to be transmitted by meat or meat products” and “that milk does not pose a quarantine threat for BTV”.

Reoviridae, Orbivirus (Epizootic haemorrhagic

OIE B Cervid Meat Virus No, negligible

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Agent Included

virus disease) transmission Never detected in Britain (WAHID, 2014). As the virus infects endothelium, all tissues of the body may be affected, however, infection in ruminants is not contagious – biological vectors (Culicoides sp.) are required (OIE Technical Disease Card). The virus deteriorates less than 24 hours after a deer dies, and cannot be spread from carcasses.

Retroviridae, Betaretrovirus (Ovine pulmonary adenomatosis)

B Ovine/Caprine Meat, cheese

Virus No, endemic

Last detected in Britain in 1996 (WAHID, 2014). BLV-infected cells are present in marketed beef and dairy products (Buehring et al., 2003). Authors detected at least one antibody isotype reactive with BLV in 74% of the human sera tested. The virus has also been found in the cellular fraction of various body fluids including milk (OIE Terrestrial Manual, 2009).

Retroviridae, Deltaretrovirus (Enzootic bovine leucosis)

B B Bovine Meat, cheese

Virus Yes, meat and meat products and untreated dairy products

Last detected in Britain in 1996 (WAHID, 2014). BLV-infected cells are present in marketed beef and dairy products (Buehring et al., 2003). Authors detected at least one antibody isotype reactive with BLV in 74% of the human sera tested. The virus has also been found in the cellular fraction of various body fluids including milk (OIE Terrestrial Manual, 2009).

Retroviridae, Lentivirus (Caprine arthritis/ encephalitis)

B - Caprine Meat, cheese

Virus No, endemic

Retroviridae, Lentivirus (Equine infectious anaemia)

B A Equine Meat Virus No, negligible transmission

Reported in Britain 2006, 2007, 2010, 2012 (WAHID, 2014). Free between 2004 and 1976 (HandistatII). Once a horse is infected with EIAV, its blood remains infectious for the remainder of its life (OIE Terrestrial Manual, 2009). EIAV can also be transmitted in blood transfusions or on contaminated needles, surgical instruments and teeth floats. It is reported to persist for up to 96 hours on hypodermic needles (CFSPH, 2009). Inapparent infected horses are safe for slaughter and human consumption of the meat. No reports were identified regarding the persistence of EIAV in carcases or meat products.

Retroviridae, Lentivirus (Maedi-visna)

B Ovine/Caprine Meat, cheese

Virus No, endemic


Rhabdoviridae, Lyssavirus (European bat lyssavirus)

- A Bats Meat Virus No, negligible transmission

Last detected in Britain in 2008 (WAHID, 2014). It is very rare for EBLVs to infect animals other than bats. On several occasions EBLV-1 has infected other animals; 5 sheep in Denmark, a stone marten in Germany, and 2 cats in France (HPA, 2013). Bats or other animals that have been dead for longer than 4 hours are no longer considered infectious for lyssaviruses. Bat or other animal blood, urine, and faeces are not considered to be infectious (Australian Government, 2013).

Rhabdoviridae, Lyssavirus B A Multiple Meat, Virus No,

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Agent Included

(Classical Rabies) cheese negligible transmission

Last detected in Britain in 2001 (WAHID, 2014). Rabies been transmitted by ingestion in experimentally infected animals, and there is anecdotal evidence of transmission in milk to a lamb and a human infant from their mothers (CFSPH, 2012). MacDiarmid et al., 1997 considered that the introduction of rabies via meat or meat products was remote. Williams (2003) concluded that the virus cannot survive long away from an animal host and does not persist in the carcase or animal products.

Rhabdoviridae, Vesiculovirus (Vesicular stomatitis)

A B Multiple Meat Virus No, negligible transmission

Never detected in Britain (WAHID, 2014). VS virus is sensitive to environmental conditions and is rapidly inactivated outside the host. There are no accounts of the transmission or suspected transmission of VS through pig meat or pig meat products (AFFA, 2001). An literature review that found no evidence of VS being excreted in milk or transmitted in milk, with AQIS (1999) concluding that milk did not present a quarantine hazard for the introduction of VS.

Togaviridae, Alphavirus (Equine encephalomyelitis - Eastern and Western)

B B Equine Meat Virus No, negligible transmission

Never detected in Britain (WAHID, 2014). Mosquito borne. Thermal inactivation point (TIP) for Alphaviruses is 58°C and virion half-life is 7 hours at 37°C (OIE Terrestrial Manual, 2009). Neither virus can survive outside the host. There is no evidence to suggest that EEE, WEE or VEE is transmitted orally (AFFA, 2001).

Togaviridae, Alphavirus (Venezuelan equine encephalomyelitis)

B - Equine Meat Virus No, negligible transmission

Never detected in Britain (WAHID, 2014). Mosquito borne. There is no evidence to suggest that EEE, WEE or VEE are able to be transmitted orally (AFFA, 2001).

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13. APPENDIX 2: INITIAL LOADING OF PATHOGEN IN PRODUCT TYPE Anthrax (Bacillus anthracis) in meat and meat products An old study comparing the infection of blood in different species suggested that animals died once a predetermined level of organism per ml of blood had been reached (107-109 bacilli per ml of terminal blood depending on species) (Lincoln et al, 1967). A review of similar studies (WHO, 2008) found similar results, including an approximate count of 108 bacilli in the terminal blood of sheep and goats, although the precise reference could not be found. The count of bacilli in pigs is known to be much lower (Redmond et al, 1997). No evidence was found to suggest the contamination levels of meat. The loading of anthrax spores, which are far more heat resistant, was also not found in the literature. In the absence of any further evidence in the literature, and from discussions with disease experts, a worst case of 105 anthrax spores was assumed in a gram of meat tissue (Worth, pers. comm. 2014). It was noted that this estimate was associated with considerable uncertainty. Brucella (B. abortus, B. melitensis, B. ovis, and B. suis) in meat and meat products and dairy products Capparelli 2008 found that of 500 water buffalo studied, most were low shedders (excreting less than 1000 CFU/ml of milk, but that “super-shedding” water buffalo may excrete up to 105 B. abortus per ml of milk. A 1971 report by the US Army summarising oral dose response information for a range of zoonotic diseases reviewed the scarce data on pathogen load in milk and dairy products for B. abortus: a level of 600-800 organisms per ml of milk was found by Harris et al, and Huddleson et al observed up to 400 organisms per ml of whole milk after 24 hours storage in an ice box. Any dairy products would be subjected to dilution factors on farm as not all from one single infected animal in cheese, milk or dried milk product. Donaldson (1997) reports that dilution factors of 5 to 10 fold are not improbable, from the concentration of infectivity in milk from an infected individual, to the concentration found in pooled products from that dairy. In the risk assessment for dairy products it was assumed that the amount of infectivity could range from 400 to 103 CFU/ml. There were no data found on the presence of Brucella in meat, however, the pathogen is a known aerosol risk for slaughtermen. It was assumed that any infectivity available in meat products would be lower than in milk, with a mean value of 400 CFU/g. Salmonella (Salmonella Gallinarum) in meat and meat products and eggs A study by Popa et al (2008) (investigating the effectiveness of probiotics on various avian infections) observed up to 105 CFU per carcase of S. Gallinarum using a carcase wash (chicken placed in bag with buffered peptone). With no further information, it was assumed that there would be 105 CFU per g, with a view to revisit the parameterisation if the risk estimate was non-negligible. No data was found for the amount of infectivity in egg products. It was assumed that there was the same loading as found in meat of 105 CFU per g. Chronic Wasting Disease (CWD) in meat and meat products CWD is a prion protein disease affecting the central nervous system. Infectivity has been detected in the brain and other central nervous system (CNS) tissues, including peripheral nerves, tonsils, spleen, lymph nodes, Peyer’s patches and lymphoid tissue in the intestines (Salman, 2003; Sigurdson et al., 1999). Levels in the CNS have been recorded 107.8 to 108.7

105

i.c. ID50/g of brain homogenate in Tg(DeerPrP) line 33 mice (Race et al., 2009), and 109.0 i.c. ID50/g in Tg(CerPrP)1536+/− mice (Johnson et al., 2012). Titres in meat were found to be contaminated with a variable range of titres. On average, incubation periods (dependent on dose) were 62% longer than the incubation period from CNS of the same animal (Angers et al., 2009), indicating a lower dose. For BSE, another prion disease in cattle, an increase of 60% in the incubation period from around 60 to over 90 months corresponded to an over 1,000 fold decrease in dose from the cattle attack rate study (Arnold, pers. comm. 2014). Highly Pathogenic Porcine Reproductive and Respiratory Syndrome (HP-PRRS) in meat and meat products The role of pig meat in the transmission of PRRS virus has been examined by several researchers. In an experimental study inoculating various strains of PRRS into piglets, viral loads in broncho-alveolar lavage fluid was infected with between 5-6 log copies per ml

(Morgan et al, 2013); in another study the absolute copy number per L of PRRSV in serum was between 100-108 for symptomatic and 10-105 for asymptomatic pigs respectively (Lin et al (2013)). Bloemraad et al (1994) recovered low levels of PRRS virus from muscle of experimentally infected pigs between 0 and 1 day after slaughter (102.8 – 103.7 TCID50/g) but not in muscle specimens held at 4ºC for two days (AFFA, 2001). Lelystad ID-DLO, Netherlands undertook an experimental feeding study of European and American PRRS strain infected meat to pigs. Muscle virus titres from 24 experimentally infected pigs were determined as below 101.8 to 103.8TCID50/g. In the absence of further information, it was assumed that the average amount of HP-PRRS in meat was between 101.8 to 103.8TCID50/g. African Swine Fever (ASF) in meat and meat products A number of estimates have been recorded for the viral titre, in haem absorbing units, in pig and warthog meat, offal and blood at various points in the incubation period with different strains of the virus (Ordas et al., 1982; Thomson et al., 1985; Mebus et al., 1997; Farez & Morley 1997; McVicar 1984; Wilkinson, 1983). From a dataset of 160 separate measurements, ranging from 3 to 109 days post inoculation, including blood, bone marrow, fat, heart, kidney, liver, lung, lymph nodes, muscle, spleen, and tonsils, the mean titre of infectivity was 104.25, with a 95th percentile of 108 HAD50/g. The highest titre recorded in the dataset was 109.5 HAD50/g in bone marrow 5 days post infection. In the risk assessment, the average titre of infectivity was estimated as a range from the average infectivity to the 95th percentile of the combined dataset, estimated as between 104.25 and 108 HAD50/g. Infectious pancreatis necrosis (IPN) in fish tissues An experimental study of goldsinny wrasse (Gibson et al, 1998), observed between <555 pfu/g and 6.5x104 pfu/g tissue. In Atlantic cod, Urquhart et al., 2009 found very high titres of virus in infected young Atlantic cod (1g and 3g) with a range of 102 to 1010 infectious units/g tissue. A risk assessment by MAF, 2007 cites that “fillet [fish] tissue, even of carrier fish, is expected to have virtually undetectable levels. Carrier salmonids had a muscle titre of 100.3 (= 2) TCID50/g.” Wechsler et al., (1986) found that with inoculation with varying doses intraperitoneally, induced correlated amount of infectivity in striped bass tissues. Striped bass injected with 103 pfu were found to contain an average of 102 pfu/g in ground tissues. Doses of 105 resulted in a range of titres from 103 to 106 pfu/g, whilst high doses of 106 pfu were found to contain a range of 102 to 107 pfu/g of ground tissue. Given that natural doses are likely to be lower than those used experimentally, it was assumed that the average initial loading of infectivity is between 103 to 106 pfu/g as seen experimentally with a dose of 105.

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Highly pathogenic Porcine Epidemic diarrhoea (HP-PED) in meat and meat products The main route of infection for PEDV is the faecal-oral route. Currently, there is little information regarding the amount of virus present in those parts of an infected pig carcase that may be consumed and enter food waste. AFFA (2001) stated from a review of the literature that no studies or reviews were identified in which PED virus was demonstrated in either muscle tissue or muscle vasculature. Although a large amount of research is on-going, there has not yet been confirmed PEDV isolated from outside of the intestinal tract (Madson, 2013), however, there are evidence of transmission of infection using swine bioassay via blood plasma products manufactured within affected countries (CFIA, 2014). For, transmissible gastroenteritis (TGE), caused by a similar coronavirus to the pathogen that causes PED, at the peak of viraemia, some tissues, such as kidney, may contain titres of TGE virus as high as 106 TCID50/g and meat scraps have introduced disease into herds (MacDiarmid, 1998). However, Farez and Morley stated in a review of pork and pork products that TGE viruses are not hazards of these commodities (1997). Intestinal tracts can be processed in sausage casings, however, PEDV may be unlikely to withstand the processing required for casings if survival characteristics are similar to those of TGE (AQIS, 1999b). The TGE infectivity titre in faecal matter has been measured as 1 x 102 pfu/ml to 7.2 x 103 pfu/ml (Woods and Wesley, 1998). It is assumed that PED may be present in meat at very low levels and also in ground meat products that may contain some offal from infected pigs. In the absence of further information, it is assumed that the average initial loading of infectivity is between 1 TCID50/ml, and the lowest levels recorded for TGE in faeces, that is, 1 x 102 pfu/ml. Given a conversion rate of 1 pfu per 0.7 TCID50, this upper estimate can be expressed as 102.15 TCID50/ml. Classical Swine Fever (CSF) in meat and meat products A number of estimates have been made for the viral titre, which is dependent on tissue type, viral strain, days post infection, and the health status of the animal exposed. From a dataset of 84 separate observations, from 4 to 25 days post inoculation, including bladder, blood, bone marrow, brain, fat, kidney, liver, lung and lymph node, muscle, skin, spleen, thymus, thyroid and tonsil, the mean titre of infectivity was 105.56 TCID50/g. The highest titre found in any tissue type was 108.9 TCID50/g in tonsil and spleen (Weesendorp et al., 2010). The loads measured in muscle were recorded as much lower, Wood et al., (1988) report the highest found in the literature of 104.9 TCID50/g in striated muscle. The highest titres from experiments at APHA with muscle from infected pigs has been 104.2 TCID50/g which was in a pig with other disease complications (APHA, unpublished, project SE4010). Titres in fats has also been found to be lower than tonsils with a similar range to muscle at 104 TCID50/g (APHA, unpublished, project SE4010). In the risk assessment, the average titre of infectivity was estimated as a range between 104.2 TCID50/g and 105.56 TCID50/g. Aujeszky’s disease virus (ADV) in meat and meat products Aujeszky’s Disease or Pseudorabies is naturally spread between animals via the nose and mouth with primary replication in the respiratory system. Pigs are the natural host for ADV, however it can infect cattle, sheep, cats, dogs and rats causing fatal disease. From a review of the literature, no information was found on the level of ADV in contaminated meat/offal or infected blood. In the absence of any further information, the titre in meat and meat products from infected animals is assumed to be relative low at 104 TCID50/g.

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Foot and Mouth Disease (FMD) in meat and meat products and dairy There are a number of reports in the literature of the viral titre of FMDV in the blood and organs of different susceptible animals, at points in the incubations period infected by different strains (Burrows, 1968; Cottral, 1969; Gailiunas & Cottral, 1966; Farez & Morley, 1997, Mebus et al 1997, Sellers 1971, Sharma & Murty 1981). During the early acute phase of disease, the tires of virus are at their greatest. In a study of 62 pigs the mean level of infection in muscle tissues was 100.03 pfu/g with a standard deviation of 100.2 (Farez and Morley, 1997). In sheep muscle, Sharma and Murty, 1981 found levels of 103.5 to 103.6 TCID50. Higher titres have been found in blood. A review of conducted on data recorded in 16 cattle samples 0.5 to 4 days post infection (Cottral, 1969, Gailiunas and Cottral, 1966, Burrows et al., 1981), 62 pig samples 1 and 2 days post infection (Mebus et al., 1997; Farez and Morley), and 15 sheep samples 1-4 days post infection (Burrows, 1968, Sharma and Murty, 1981). The average titre across species was 103.77 TCID50 per ml, with a minimum of 101 TCID50/ml. The maximum titre found in the literature was 1010 pfu/ml from bovine heart muscle at the peak of clinical onset (Burrows et al., 1981 cited by Pharo, 2002). For infected individual milk samples, titres have been recorded as high as 106.6 TCID50/ml, 106 TCID50/ml, and 105.5 TCID50/ml (Burrows et al., 1981 cited by Pharo, 2002; Hyslop, 1970) from infected individual cattle. However, only titres of 102.2 TCID50/ml were recorded when the on-farm milk tanker was analysed demonstrating the dilution effect of the herd, prior to any processing into dairy products. In the risk assessment, in the absence of any further data on the average titre of FMD infectivity, this parameter was estimated as 103.77 TCID50/g in meat and meat products, and equally likely between 102.2 and 106.6 TCID50/ml for dairy products. Enzootic bovine leukosis (EBL) in meat and meat products and dairy EBL is a disease of adult cattle caused by the bovine leukaemia virus (BL V). Cattle may be infected at any age with most infections subclinical. However, a percentage of cattle (~30%) develop lymphocytosis, and smaller proportions develop tumours in internal organs (OIE, Terrestrial Manual). Of seven BLV-infected cattle in Japan, four had proviral loads of over 1000 copies per 105 peripheral blood mononuclear cells (PMBCs); the maximum was 10,689 copies per 105 cells (Panei et al, 2013). Another study investigating the variability in viral load over a period of two years observed one cow with up to 100,000 copies per 105 PMBC cells (Kramme et al, 1994). In the absence of any further information, the initial loading in meat and meat products and dairy from infected animals is assumed to be relative low at 104 cells/g. Highly Pathogenic Avian Influenza (HP-AIV) in meat and meat products and eggs A model fitted to previous experimental study data on duck cloacal swabs (used as an indicator of faecal environmental contamination) predicted a maximum of 103 50% Egg Infective Doses (EID50s). Several studies investigating thermal inactivation of HPAI in chicken meat observed contamination levels of between 102.8 – 108.5

EID50/g of meat or muscle (Swayne & Beck, 2005; Tumpey et al, 2002). The most naturally realistic experiment (where birds were infected intranasally with “natural” levels of HPAI), resulted in a levels of contamination of breast meat at 107.5 EID50/g and between 107.8

and 108.5 EID50/g thigh meat

(Thomas & Swayne, 2007). In the absence of any further information, the average initial loading of infectivity in meat and meat products is assumed to be between 102.8 – 108.5

EID50/g. A previous avian influenza risk assessment for broiler meat and egg products was developed by the Food Safety and Inspection Service of the US Department of Agriculture

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(FSIS, 2010). They have reviewed previous studies estimating levels of infection within eggs and egg products; they found a range of 1.8-5.6 logs EID50/ml of internal egg contents, and then assumed a point value contamination level of 4.9 logs EID50/ml. In the risk assessment, the average initial loading in egg products is assumed to be a mean of 104.9 EID50/g with a minimum value of 101.8 EID50/g and maximum value of 105.6 EID50/g. Newcastle Disease (ND) in meat and meat products and eggs An experiment attempting to replicate natural infection of chickens with HPAI and Newcastle Disease (Thomas et al, 2008) observed contamination rates of thigh and breast meat of 6.8 and 6.4 log EID50/g respectively, although contamination decreased over time. In the absence of further information, the average initial loading of infectivity in meat is assumed to be between these values. There is little evidence to suggest what the contamination rate of naturally infected eggs would be, but an experimental study suggests that shell surface contamination would be between 0.97 – 6.7 log EID50 per egg (Swayne & Miller, 2013). With no further information to inform the risk assessment, these values are used as the minimum and maximum values for the initial loading of infectivity per egg. Sheep Pox and Goat Pox (SPP and GTP) in dairy products Within in the time available, and from a search of the literature, viral titres of these pathogens in milk was not found. In the absence of any further information, the initial loading in dairy products from infected animals is assumed to be relative low at 104 TCID50/g. Swine Vesicular Disease (SVD) in meat and meat products SVDV has been measured in the different organs of infected pigs with a range from 100.2 pfu/g in muscle to 106.2 pfu/g in lymph nodes (Mebus et al 1997; Mann & Hutchings, 1980; McKercher, 1974). From a dataset of 149 observations, from 1 to 10 days post inoculation, including blood, bone marrow, fat, kidney, lymph node, muscle, skin, spleen and tonsil, the mean titre of infectivity was 103.19 pfu/g. With no further information the average initial infectivity in meat products from animals infected with SVD is estimated to be 103.19 pfu/g.

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14. APPENDIX 3: CONVERSION OF ID50 UNITS INTO ORAL DOSES Anthrax (Bacillus anthracis) All mammals are susceptible to Anthrax with varying sensitivities. The infectious dose required for B. anthracis is strongly dependent on the pathogen strain, route of infection, the species, breed and the state of health of the animal concerned. The relationship between experimentally determined ID50s and doses encountered by animals acquiring the disease naturally is poorly defined (WHO, 2008). Pigs are relatively resistant to the organism. The pathogen is not an invasive organism by inhalational or ingestion routes, with the infectious dose in the order of tens of thousands, even in species regarded as susceptible, as shown by a summary of the available data (WHO, 2008):

Oral infectious dose for sheep was reduced from 200,000 to 51,000 spores if the sheep were starved for a few days.

Oral administration of 150 million spores proved fatal to most cattle.

Ingestion ID50s in guinea-pigs and rabbits exceeded 108 spores.

100–250 spores of a strain isolated from a kudu in the Kruger National Park consistently resulted in death from anthrax when administered parenterally in impala while the oral ID50 with the same strain in these animals was approximately 15 million spores.

In a study on 50 pigs given doses of 107–1010 spores in feed containing grit, the majority showed clinical illness with recovery, and just two died with confirmed anthrax 6 and 8 days respectively after ingestion of the spores; these were estimated to have received 1.6 x 107 and 7.8 x 107 spores respectively.

Virtually nothing is known about the relative infectivity of vegetative cells as compared to spores and the possible importance of this to oral infectious dose (WHO, 2008). In pigs with the pharyngeal form of ingestion anthrax from consuming meat and bones from infected carcases, the material would contain both vegetative cells and spores. The intestinal form from consumption of meat and bone meal is associated with spore consumption. In the absence of further information, it was assumed that the oral dose for pigs was between 107–1010 spores, and for sheep between 51,000 to 200,000 spores. Brucella (B. abortus, B. melitensis, B. ovis, and B. suis) From a review of the literature, the infectious dose via ingestion is not known for Brucella species. There are more data available on parenteral and conjunctival ID50 values. Elberg (1959) determined the subcutaneous injection ID50 for B melitensis in goats at 2.5 x 104 to 5.0 x 104 CFU. Bailey (1986) estimated the ID50 for B ovis via the intraperitoneal route for sheep as 6.6 x 104 CFU with 95% confidence intervals (1.2 x 104, 4.1 x 105). Verger (1971) cited intragastric ID50 values (95th confidence intervals) with B. melitensis and mice as experimentally estimated as 458 (16.3, 3500) cells and 700 (126, 3850) cells from two different experiments. By combining these data with other experimental data with intraperitoneal injection with the same bacterial strain, Verger estimated that the relative efficiency of infection via the different inoculation routes in mice of 1 parenteral (intraperitoneal) to 0.001 intragastric (Verger, 1971). If this conversion was applied to livestock, the oral ID50 could be extrapolated as in the order of 2.5 x 107 to 5 x 107 cells for B melitensis in goats and 6.6 x 107 CFU for B ovis in sheep. No data was found for the oral dose of B. abortus or B. suis.

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With no further information, in the risk assessment it was assumed that the oral dose for B melitensis was between 2.5 x 107 to 5 x 107 cells, for B ovis 6.6 x 107 CFU, and taking the conservative estimate of 2.5 x 107 for B. abortus and B. suis. Salmonella (Salmonella Gallinarum) The dose required to initiate infection is influenced by the physiological state of the bacteria, the matrix in which the bacteria are consumed and the degree of resistance of the host. A high fat matrix is more protective. Audisio et al., 2002 investigated the virulence of strain INTA 91 in chickens. The mean lethal dose of orally administered culture was 2.04 x 108

CFU per chicken (Audisio et al., 2002). No further information could be found regarding the oral ID50 for the bacterium and this value was therefore used in the risk assessment. Chronic Wasting Disease (CWD) CWD is known to infect mule deer, white-tailed deer, black-tailed deer, red deer, elk and moose. Of these species, only red deer populations are present in Britain. There are no data on the susceptibility of the other free-ranging deer species present in Britain (muntjac, sika, Chinese Water deer) to CWD (Kosmider et al., 2012). Further experimental studies would be required to investigate the susceptibility of these species to CWD. The oral minimum infectious dose or dose to infect 50% of individuals exposed is not known. Limited oral feeding experiments have been carried out. 5g of infected brain homogenate (elk and white tailed deer) was fed to three reindeer which caused infection of two of the deer identified by biopsy (Mitchell et al., 2012). 3g of elk infected brain homogenate (5 ml of inoculum made from ground brain and 40% weight/volume of saline) was orally fed to four red deer which caused infection in all four deer identified by immunohistochemistry and ELISA (Balachandran et al., 2010). Such experiments indicate that the ID50 is lower than 3 g of brain, however, the sample sizes are small for making extrapolations. For other prion diseases, the oral infectious dose is low. The estimate of a cattle oral ID50 for BSE is 0.15 g of infected brain material (Konold et al., 2012). In the absence of further information it may be assumed that the ID50 for CWD is as low as that estimated for BSE, and that the relationship between incubation period and dose is the same for CWD as other prion diseases such as BSE in cattle. Based on the CWD incubation period for inoculated transgenic mice, this would result in an estimate of a deer oral ID50 for CWD of 150g of infected muscle meat. It needs to be highlighted that this estimate is associated with considerable uncertainty due to the extrapolations made with BSE. Highly Pathogenic Porcine Reproductive and Respiratory Syndrome (HP-PRRS) Little information was available in the literature for the oral infectious dose of the highly pathogenic strain of the PRRS virus. From oral inoculation studies the ID50 for oral routes of exposure to strain VR-2332 was estimated to be 105.3 TCID50 with 95% confidence intervals of a value between 104.6 and 105.9 TCID50 (Hermann et al., 2005). Lelystad ID-DLO, Netherlands undertook an experimental feeding study of European and American PRRS

strain infected meat to pigs. Authors indicated that there were instances where virus was undetectable in culture, indicating that the minimum infectious dose was smaller than 101.8 TCID50/g tissue the detection limit of the assay (Lelystad, 2000). Magar, 1995 had previously reported a high titre (107 TCID50/g) required for oral infection (cited by Lelystad,

2000). In the absence of further information the average oral ID50 is estimated as a mean of 105.3 TCID50 with 95% confidence intervals of 104.6 and 105.9 TCID50.

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African Swine Fever (ASF) Experimental data provided by McVicar (1984) examined the response of a group of pigs across a range of doses of ASF, and concluded that the ID50 dose for ingested ASF was a mean of 104.3 HAD ID50 (McVicar, 1984). Infectious Pancreatic Necrosis (IPN) The infectious oral dose for IPNV is difficult to experimentally assess. Experiments have been carried out by bath immersion with the virus and by intraperitoneal injection. It is assumed that intraperitoneal injection into the peritoneal space around the organs and intestines is more likely to mimic the conditions of ingestion of IPNV than through water immersion, although any feed not consumed may break down in the water and thus release any infectivity into the water. Urquhart et al., (2008), found that the minimum dose required to induce infection in Atlantic salmon post-smolts was <10-1 TCID50/mL by bath immersion (4 h at 10°C). Swanson and Gillespie (1982) injected 105 TCID50 into young Brook Trout. Virus was consistently recovered from the blood of the intraperitoneally inoculated fish. Wechsler et al., (1986) injected striped bass aged 60 to 180 days with a range of doses. Infection was initiated with the lowest dose of 103 pfu per fish. However, intraperitoneal injection avoids the aggressive gastrointestinal conditions experienced following oral administration, and therefore, ingested infectious doses are likely to be higher than those via intraperitoneal injection. In the absence of further information it is assumed that the oral infectious dose for IPNV is greater than 103 pfu per fish, with a range of 103 pfu to 104 pfu. Highly Pathogenic Porcine Epidemic Diarrhea (HP-PED) Research suggests that PEDV is highly infectious with an extremely low oral minimum infectious dose. Two highly virulent PEDV field strains were inoculated orally into 5 piglets each at 103.0 TCID50/mL and 103.1 TCID50/mL (Wang et al., 2013). All 10 piglets became infected (100% of those exposed) indicating that the oral infectious dose to infected 50% of those exposed is lower. Serial 10-fold dilutions of PEDV (clarified homogenate of intestinal mucosa from an infected piglet) in piglets found clinical signs of gastroenteritis with 10-2 to 10-8 dilutions (Goyal, 2014). No clinical signs were seen in piglets inoculated with 10-9 to 10-

12 dilutions. For, transmissible gastroenteritis (TGE), caused by a similar coronavirus to the pathogen that causes PED, piglets can be infected by a dose as low as 10-100 virus particles, while older pigs (5-6 months) require higher doses (MacDiarmid, 1999). In the absence of further information it was assumed that the oral ID50 was 102 TCID50/mL. Classical Swine Fever (CSF) A review of the published literature did not establish the oral ID50. Intranasally the infectious dose has been estimated as 398 TCID50 (102.6 TCID50) with challenge inoculation of the virulent strain Brescia 456610 (Bouma et al., 1999). Research work has been recently completed feeding pigs with a highly virulent strain and moderately virulent strain (APHA, SE4010). Six pigs were fed with oral bait blister packs filled with dilutions of cell culture propagated virus in 1.5ml cell culture media to encourage the chewing of inoculum in the oral cavity. For strain UK2000/7.1 the oral ID50 was estimated as 104.21 (95% confidence intervals 103.57 to 104.79. The highly virulent Brescia strain oral ID50 was estimated as 105.47 (95% confidence intervals of 105.1 to 105.8) (Crooke, unpublished, APHA, 2014). In the risk assessment, the oral dose was estimated as a mean of 105 with 95% confidence intervals 103.57 to 105.8.

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Aujeszky’s Disease (AD) The infectious dose required to initiate infection in pigs is dependent on the age of the animal and the strain of the virus. In the OIE Terrestrial Manual, in order to establish passive immunity to AD, pigs should be inoculated by the nasal route with 102 LD50 (OIE, 2008). Ceriatti and colleagues (1992) intranasally inoculated ten pigs with 105 TCID50. The virus was isolation from nasal swabs from 7 pigs, and 9 of the ten developed neutralizing antibodies. Tozzini (1981) orally infected four young wild pigs with 105 TCID50 to 106.3

TCID50. All four developed specific neutralising antibodies. Therefore, although four is a small sample size, it would suggest that the oral ID50 value is below 106.3 TCID50. In the risk assessment a value of 105 TCID50 was used for the oral dose. Foot and Mouth Disease (FMD) The infectious dose required for FMDV is strongly dependent on the route of exposure and on the susceptible species exposed. Cattle injected via the tongue with 1 TCID50 may become infected, whilst a higher dose of 10-100 TCID50 is required for aerosol infection (Sutmoller et al., 2003). The dose to infect cattle by the oral route is cited as in excess of 105.8 TCID50, and 106 TCID50, whilst for a pig the oral dose may be lower at 105 TCID50 (Donaldson, 1997; AVIS, 2002). As is the case with other ruminant, sheep and goats are highly susceptible to infection with FMD virus by the aerosol route, with as little as 20 TCID50 being sufficient for infection. In the absence of further information, the oral dose for pigs was 105 TCID50, whilst for cattle 105.8 TCID50 to 106 TCID50 was used. Enzootic Bovine Leukosis (EBL) The number of infected lymphocytes necessary to transmit infection varies between animals. The median infectious dose for intradermal injection of lymphocytes into sheep has been determined to be 2000 cells (Stirtzinger et al., 1988). Burny and Mammerickx, (1987) in a review stated that 1,000 lymphocytes was the minimum injected dose found for cattle. The number of lymphocytes in the blood varies widely between host animals and can increase from infection with BLV. Levels in infected sheep have been found to vary between 7.8 x 103 to 925.9 x 103 per mm3 of blood (Mammerickx et al., 1980), or 7.8 x 106 to 925.9 x 106 per mL of blood. However, from the literature an ingested dose for EBL was not found. Given the injected dose is 103.3 cells, it is likely that the oral dose with an adverse gastric environment would be several magnitudes higher. Therefore an estimate of 105 cells was used in the risk assessment. Highly Pathogenic Avian Influenza (HP-AI) The dose of HPAIV required to infect birds with disease is dependent on the virus strain, route of infection, the bird species, age of the bird and the immunity status. Many studies have been undertaken to quantify the susceptibility of poultry species to different strains of the virus to understand the epidemiology of the disease and occurrence of outbreaks. The majority of experimental data has been generated with intranasal inoculation. Swayne and Slemons, (2008) estimated the intranasal median EID50 for isolates for chickens ranged from 102.6 EID50, whereas for isolates of turkey origin, the dose required was higher, with a median of 103.9 EID50. For a strain of H7N2, Suzuki et al., 2010 summarised previous research which found that the intranasal dose varied between 102.8EID50 in chickens, 100.8EID50 in turkeys and 103.5EID50 in Pekin ducks (Suzuki et al., 2010). Given that the oral dose is likely to be higher than that inoculated intranasally, it was thought likely that the oral ID50 would be higher than 103.9 EID50, with that value used in the risk assessment.

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Newcastle Disease (ND) Alexander found that the median oral ID50 for strain Herts 33/56 was 104 EID50 for 3 week old chickens (Alexander et al., 2006). With no further information, this point value was used in the risk assessment. Sheep Pox and Goat Pox (SPP and GTP) These viruses are primarily spread between animals by direct contact with infected animals, contaminated fomites, and the respiratory route. From a review of the literature an ingested dose was not found. Blaha (1989) is cited as stating that it is not possible to infect animal experimentally via the oral route. Therefore, in the risk assessment a relative high oral dose has been assumed of 106 TCID50. Swine Vesicular Disease (SVD) For SVD the only data that could be identified was an estimate of the oral ID50 in pigs of

106.8 pfu (Mann and Hutchings 1980) based on six recipient animals, which was used as a point value in the risk assessment.

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15. APPENDIX 4: THERMOSTABILITY OF PATHOGENS IN PRODUCT BY PROCESSING CRITERIA

Anthrax (Bacillus anthracis) in meat and meat products The vegetative (growing) form of B. anthracis is relatively labile: it is killed by 60ºC dry heat for 30 minutes (Williams 2003). Anthrax vegetative cells survived 3.5 but not 4 min at 70ºC (MDA, ref). Spores are much more robust, requiring 140ºC dry heat for up to 3 hours for inactivation (Buxton and Fraser 1977, cited in Williams 2003). Moist heat destroys spores in suspension after wet heat at 100oC for 10 min (cited in Spotts Whitney et al 2003) and at 100-115°C after 14.2 minutes (Bohm 1990, cited in Williams 2003) However, in bone meal (and potentially other meals), these conditions have been shown to be insufficient to inactivate spores: contaminated bone meal was found to be infective after 15 minutes of steam treatment at 115oC degrees or 3 hours with dry heat at 140oC (De Kock et al 1940, cited in Williams 2003). It has been recommended that to ensure bone meal is free of anthrax spores, it would need to be heated to 150oC for at least 3 hours (cited in Williams 2003), or under pressured conditions (a one-log reduction can be achieved after 4 min with pressurization at 500 MPa and 75°C (Cléry-Barraud et al, 2004). In the risk assessment, it was assumed that anthrax spores were not inactivated at 70ºC, decreased by 3 logs at 100ºC, and were inactivated at 130ºC (wet heat). Brucella (B. abortus, B. melitensis, B. ovis, and B. suis) Brucella spp. are highly heat-labile. Inactivation was shown by Carpenter and Boak (1928a-c, cited in Kronenwett et al., 1954) in a series of experiments in 1928 to occur after 15min at 60oC and 61.1oC, 10 min at 62.8oC, and 30-60 sec at 71.1. These findings are supported by additional early studies (Kronenwett et al., 1954; Davies and Casey, 1973, cited in Williams 2003 ), and in a later experiment where raw, naturally-infected milk was inoculated into guinea pigs and showed that 30 min at 63oC and 15 sec at 72oC were sufficient to inactivate B. abortus (Van den Heever et al., 1982). Some variation has been shown to occur between B. abortus strains, but it is not thought to be significant (Kronenwett et al., 1954). No references were found on the persistence or inactivation of Brucella spp. in carcases or meat products. AQIS (1999a, cited in Williams 2003) lists bovine brucellosis among those diseases “unable to be transmitted via meat or meat products”. B. melitensis has been shown to be inactivated at: between 7.5 and 10 minutes at 60oC; between 5 and 7.5 minutes at 61.1°C; less than 5 minutes at 62.8°C (Mitscherlich and Marth, 1984, cited in Williams 2003). Very little specific information could be found on the time-temperature inactivation curves of B. melitensis, B. ovis and B. suis, but it can be assumed that they are not dissimilar to B. abortus. In the risk assessment Brucella spp. was assumed to be inactivated by all three temperature-time conditions. Salmonella (Salmonella Gallinarum) Salmonella spp. are heat-sensitive and perish after being heated to 55°C for 90 min, or to 60°C for 12 min in meat. Other studies estimate that most spp. are destroyed by 56°C for 10 to 20 minutes and will not survive temperatures above 70°C (Franke-Whittle et al., 2013). Little data is available on the inactivation of S. Gallinarum specifically, however, a cocktail of Salmonella spp. (incorporating several serovars of chicken origin) in chicken broth underwent a one-log reduction within 0.41 minutes of being heated to 62°C (Juneja et al. 2001). In meat, chicken-origin serovars were more heat-resistant, undergoing a one-log reduction after 0.59 min at 65°C (Juneja et al. 2001). It should be noted that heat sensitivity

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of Salmonella spp. is considerably less under low water-activity, high-fat conditions (Juneja et al 2001b, Mattick et al 2001). To account for the occurrence of high fat conditions, it was assumed in the risk assessment that there was a 3 log reduction at 70ºC, with inactivation at 100ºC and 130ºC. Chronic wasting disease (CWD) in meat and meat products Prions are notoriously difficult to degrade solely using heat and many factors will affect inactivation, including tissue condition (e.g. macerated tissue), the dehydration state of the agent and surface effects. Experiments conducted specifically with tissues from deer and elk infected with CWD demonstrated that the prion was partially inactivated by long-term (90 days) incubation at two temperatures; 55 and 80°C (Triantis et al., 2007). After the time interval, only traces of the protein were found by western blot. Using other prion strains, Prusiner et al. (1981) conducted experiments with hamster adapted scrapie under different experimental conditions. Controls included 1 hour at 70°C in supernatant solution of unspecified pH. Scrapie titre reductions of 7.3 log ID50 /ml were measured (Prusiner, et al., 1981). Incubation in water for 18 hours at 65°C had little effect on four TSE strains (301V mouse adapted BSE, cattle BSE, sCJD, and Sc237) with estimates varying between 0.5 and 2.4 log reduction (Giles et al., 2008). It was assumed that at the lowest temperature conditions of 70°C for 30 minutes there was no effect on the prion associated with chronic wasting disease. At 105°C with recombinant prion protein (strain 90-231) in a water lipid mixture, Appel and colleagues found that there was little reduction in infectivity after 20 minutes, with approximately 0.7 log reductions (Appel et al., 2001). It was assumed that with processing conditions set at 100°C for 1 hour there was no effect on the prion associated with chronic wasting disease. At higher temperatures, the M1000 prion strain can withstand autoclaving (i.e. wet heat) at 134-138°C for 18 minutes (Raven and Sutton, 2002, Lawson et al., 2007). Most of the infectivity loss occurred within the first 20 minutes. Some data suggests that temperature should not exceed 134°C, with declines of effectiveness of autoclaving at 136°C to 138°C. Giles and colleagues measured the reduction of infectivity in four TSE strains, 301V mouse adapted BSE, cattle BSE, sCJD, and Sc237, heated to 134°C for 30 minutes with log reductions of >8.1, 3.2, >7.2 and >7.2 (Giles et al., 2008). Complete reduction of BSE brain homogenate at 134°C took 2 hours. For 263K prions, a Syrian hamster-adapted scrapie strain, reductions of 3.2 log ID50 to 7.5 log ID50 have been reported for a 30-min incubation at 134°C under comparable conditions (Muller et al., 2007). It was assumed that at the highest processing conditions of 130°C for 30 minutes (wet heat) there was at least a 3 log reduction of CWD infectivity. Highly Pathogenic Porcine Reproductive and Respiratory Syndrome (HP-PRRS) Little information is available on the temperature inactivation curve of this virus. However, PRRS virus in manure and aqueous media was shown to have a half-life (0.301 log reduction) of 2.9 and 8.5 min, respectively, at 63oC, and of 0.36 and 0.59 minutes at 80°C (Linhares et al 2012); another study of the virus in media indicated a half-life of 6 min at 56ºC (Bloemraad et al 1994). These results indicate that at worst, a 1-log reduction could be expected after 30 min at 70°C, and a 15 log reduction after 60 min at 100oC. Inactivation was assumed at 130°C. African Swine Fever (ASF) in meat and meat products In numerous experiments with pig serum, Montgomery (1921) found that the temperature

required to inactivate ASFV was 60C. A total of 56 trials were conducted at this temperature

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for 10, 15 and 20 minutes following inoculation. All results were negative for ASFV.

McKercher and colleagues found that a temperature of 69C was the critical internal temperature needed to inactivate ASFV in a variety of meat products including bone marrow, lymph nodes and clotted blood (McKercher et al., 1978). There is no available data on the survival of ASFV in offal such as liver, kidneys or lungs. However, there is no evidence that ASFV survival times in offal tissues are longer than in meat held at room temperature. The National Institute for Agronomical Research, Madrid, conducted a number of

experiments to investigate ASFV survival in canned pork. Tins were heated at 65C and

75C for time intervals of half, one and two hours. All heat-treated tins gave negative results

(Sanchez-Botija, 1982). When partially cooked canned hams were heated to 60C, ASFV could not be recovered (Ordas et al., 1982). Therefore, it was assumed that ASFV was

inactivated by heating to a core temperature of 70C for 30 minutes, and increasing temperature controls. Infectious Pancreatic Necrosis (IPN) Infectious pancreatic necrosis virus is highly resistant to heating. One study showed a 2-log reduction after 30 min at 60°C (MacKelvie and Desautels 1975), however, in recent work, it has been shown to have D-values in aqueous media of 16 min at 70°C at pH7, and 54 min at pH4 at the same temperature (Nygaard et al 2012). The D value or decimal reduction time, is the time required at a certain temperature to kill 90% of pathogen present. It should therefore be assumed that, at the lowest of the temperature controls, minimal change in viral load might be achieved under low-pH conditions. Risk assessments conducted in Norway indicated that the reduction in viral load in fish tissue homogenate after 20 min at 76°C - at either pH 4 or pH 7 - is only 3-log (Norwegian Scientific Committee for Food Safety, 2012). A one-log reduction of virus in supplemented medium was achieved after 1.17 minutes at 90°C (Nygaard et al 2012). These results indicate that at worst, a 2-log reduction could be expected after 30 min at 70°C, and a 25 log reduction after 60 min at 100oC. Inactivation was assumed at 130°C. Highly Pathogenic Porcine Epidemic Diarrhea (HP-PED) Culture-adapted PEDV loses infectivity when heated to 60ºC for 30 minutes, but is moderately stable at 50°C (Pospischil et al., 2002). In faeces, the virus was inactivated after 10 min at 71°C, although 10 minutes at 62.8°C was insufficient to inactivate (Thomas et al 2013). It is therefore assumed that all the temperature conditions of interest were sufficient to inactivate the virus, although this could be considered borderline, and strict adherence to temperature controls will be needed. Classical Swine Fever (CSF) CSFV is readily killed by pasteurisation processes or cooking. Stewart and co-workers

(1979) found that cubes of pork cooked with a ‘flash’ temperature of 71C for 1 minute

caused inactivation of the virus. Heating to 69C for 15 minutes (McKercher et al., 1980) and

65C for 30 minutes (Steward et al., 1979) have also produced negative results. Fresh samples of offal (liver, kidney, and lung) have been shown to be contaminated with viable CSFV (Wood et al., 1988). There is no evidence that CSFV survival times in offal tissues are longer or shorter than in meat tissues. There are differences in the inactivation values between tissue types (muscle meat and fat), however, the differences are more pronounced

at lower temperatures (below 25C) (APHA, unpublished, SE4010). Therefore, it is assumed

that CSFV is inactivated by heating to a core temperature of 70C for 30 minutes, and increasing temperature controls. Data from research work recently completed on the survival

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of CSF in meat products at different temperatures are consistent that heating at 70C for 30 minutes should be sufficient (APHA, unpublished, SE4010). Aujeszky’s Disease (AD) Core temperatures of 70ºC or higher must be reached in order to inactivate the virus (McDiarmid, 1999). In culture medium, a one-log reduction after 1 minute at 65°C has been shown (Turner et al., 2000). In slurry, the virus has been reported to be inactivated after 10 minutes at 55°C (Williams 2003) and conversely, reduced by 4.8 log after 3 min at 62°C and by 3.7 log after 3 minutes at 65°C (Turner et al, 2000). Taking the most conservative of these findings, it was therefore assumed that a 30-log reduction in the virus was achieved at the lowest of the temperature controls. At higher temperatures the virus was asssumed to be inactivated. Foot and mouth disease (FMD) in meat and meat products and milk Several thermal processes have been described which effectively destroy FMDV viral activity in meat and meat products. Temperatures over a range of 68.3 to 93ºC (Blackwell et al., 1989) have been used to achieve FMDV inactivation. In moist tissue products such as broths, soups, extracts etc it is reasonable to work on the basis of FMD virus being destroyed by 80-100°C for a ‘short time’ or 70°C for 25 minutes (Williams, 2003). However, there is other evidence showing survival of the virus above 70°C: Lasta et al. (1992, cited in Ryan et al 2008) found infectious virus after heating cattle meat and lymph nodes directly in water at 78°C for 20 min. In another older study, infectious virus was found in samples of epithelium heated to 70°C for 6 hours (Dimopoullos et al., 1959, cited in Ryan et al., 2008). Blackwell et al (1982) demonstrated viable virus (using cell culture or cattle inoculation) in lymph nodes from experimentally-infected steers after 2 hours at 69°C. Inactivation occurred at 82°C after 2 hours; and at 90°C after 1 hour. The addition of NaCl enhanced survival of the virus at 90°C – infectivity was shown after 30 minutes at this temperature in the presence of salt (Blackwell et al 1982). Multiple data points demonstrating reduction in viable virus were plotted by Gale et al. (2012), and fitted to a curve that estimates that 5.2 minutes are required at 70°C for a one-log reduction in virus. This indicates that at least a 5-log reduction would be observed after heating at 70°C for 30 minutes. It is worth noting that the virus may remain active in dried tissue products after 2.5 hours at 70°C, 5 minutes at 110°C, and 1 minute at 130°C (cited in Williams 2003). Ryan et al. (2008) has summarised the temperature sensitivity of FMD virus in milk. Infectivity has been detected by cattle inoculation after pasteurisation at 65°C for 64 minutes (Hyde et al 1975). A 2-log reduction was shown after 30 min at 63°C by Aly and Gaber, 2007 (cited in Donaldson, 2011). The virus is more sensitive to heat at lower pH: at pH 6.7, 17 s at 72°C produced a 5-log reduction in titre, whereas at pH 7.6, 55 s was required to achieve this (Ryan et al., 2008). HTST pasteurisation of whole and skim milk to 72-95°C for 19-36 seconds decreased virus infectivity by 4 log (Tomasula et al. 2007). Possibly a fraction of the virus was protected by the milk fat and the casein proteins. Pasteurisation to 135°C should inactivate the virus under natural conditions (Ryan et al. 2008). Again, the virus may survive well in dried products: milk and skimmed milk used to produce milk powder demonstrated a 5.4-log reduction in infectivity after being heated to 80–90°C for 30 s (Ryan et al, 2008). It can therefore be assumed that at 30 minutes at 70°C, inactivation of FMD is not certain, although it will occur at the higher control temperature. It was assumed in the risk assessment that heating the virus to 70°C for 30 minutes produced a 5-log reduction in titre, with inactivation assumed at higher temperatures. Enzootic Bovine Leukosis (EBL)

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This disease is caused by bovine leukaemia virus (BVL), which is heat-labile. BVL is inactivated after 30 minutes at 47°C or 62.8°C, both in milk and in culture media (Moore et al 1996) Additional studies on short-term heat treatment have demonstrated non-infectivity of the virus in aqueous media kept for 30-60 seconds at >60°C (Baumgartner et al., 1976), or at 72°C for 15 sec (Moore et al., 1996). Experimentally-inoculated milk subject to high-temperature, short-time pasteurisation (typically 71.5 to 74°C, for 15-30 seconds) also failed to show infectivity in biological assays (Baumgartner et al, 1976). Therefore, it was assumed

that EBL was inactivated by heating to a core temperature of 70C for 30 minutes, and increasing temperature controls. Highly Pathogenic Avian Influenza (HP-AI) HPAI is heat-labile and temperatures of >70°C have been considered sufficient to inactivate the virus (Williams, 2003). However, in one study, where high concentrations of H5N1 virus were kept in aqueous media, infectivity was shown in some samples kept at 65°C for 60 min, 70°C at 45 min, and 75°C at 30 min (Wanaratana et al., 2010). These results are inconsistent with other reports (and may not be applicable to field conditions). In other experiments H5N1 HPAI, present at high titres in chicken meat, underwent a one-log reduction after 33.1 sec at 61°C, 0.5 sec at 70°C, and 0.073 sec at 73.9°C (Thomas and Swayne 2007). H5N1 HPAI in chicken meat was also completely inactivated after 70°C at 5, 10, 30 or 60 seconds (Swayne 2006). Therefore, it was assumed that HPAI in meat and

meat products was inactivated by heating to a core temperature of 70C for 30 minutes, and increasing temperature controls. H5N2 HPAI in egg products is also heat-labile: virus in homogenised whole egg, liquid egg, and 10% salted yolk underwent a one-log reduction in less than 20 seconds at 63°C (Swayne and Beck, 2004). In eggs, inactivation of H5N2 HPAI in yolk and albumin occurred at 57°C after 10 min (King 1991, cited in De Benedictis et al 2006). In fat-free egg products, another H5N2 virus underwent a 1 log reduction after 0.4 min (24 sec) at 59°C (Chmielewski et al, 2011). By contrast, in aqueous media, HPAI H7N2 took 1 minute to undergo a one-log reduction at 61°C (Chmielewski et al, 2011). In dried egg white, H5N2 HPAI has been shown to persist for much longer: it took 0.2 days (4.8 hours) at 63°C before a one-log reduction was achieved (Swayne and Beck, 2004), and has been shown to remain infectious after 7-10 days at 54.4°C in standard production of dried egg white. However, treatment at 67°C for 15 days inactivates HPAI whilst preserving the quality of the egg white product. For HPAI in egg products it was assumed in the risk assessment that there would be

between a 2 and 3 log reduction at 70C for 30 minutes, with inactivation at increased temperatures. Newcastle Disease (ND) The time required for inactivation of different strains of Newcastle Disease after heat treatment has been summarised by McDiarmid (1999) as: between 5 minutes and 6 hours at 56°C; 7-30 minutes at 60°C; 50 seconds at 70°C, and 1 minute at 100°C for 1 minute. These times, however, are influenced by the food matrix in which the virus is present. In culture media, the virus has been shown to take 0.91 or 0.82 minutes, depending on the strain, for a one-log reduction at 70°C (Chmielewski et al 2011b). In meat, NDV undergoes a one-log reduction at 82, 40 and 29 seconds at 70°C, 74°C, and 80°C, respectively (Alexander and Manvell 2004). It can therefore be assumed that a 21-log reduction, as observed in meat, or a 32-log reduction in other non-preserved food matrices, will occur under the lowest of the temperature controls. Inactivation at higher temperatures is assumed.

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In homogenised whole egg, liquid egg, and 10% salted yolk, one-log reductions of several strains occur within 24 seconds at 63°C (Swayne and Beck, 2004). In dried egg white, by contrast, virus could persist up to 6 hours at 63°C (Swayne and Beck, 2004). This means that virus could persist at 70°C, although it is assumed that it is unable to do so at higher temperatures. It was assumed in the risk assessment that over all egg products, the average

reduction was 4 log at 70C for 30 minutes, with inactivation at increased temperatures. Sheep Pox and Goat Pox (SPP and GTP) Cell-adapted goat pox is completely inactivated at 50°C for 450 minutes and 56°C for 30 minutes (Talhouk and Al-Zein, 1986). Cell-adapted sheep pox is marginally more heat-sensitive (El-Awar and Al-Zein, 1986). However, in both these studies, the virus was contained in aqueous media; it is possible that persistence in milk could occur, even after high-temperature, short-time pasteurisation (HTST), as milk is known to be protective (Williams 2003). Information on time-temperature curves in this product is not available. Therefore, it was assumed that SPP and GTP were inactivated by heating to a core

temperature of 70C for 30 minutes, and increasing temperature controls. Swine Vesicular Disease (SVD) in meat and meat products

Available data suggests that 69C appears to be the critical internal temperature required to inactivate SVDV in a variety of meat products (Heidelbaugh & Graves 1968; McKercher et al., 1975 and 1978; Loxam & Hedger, 1983). McKercher and co-workers (1980) found that SVDV was inactivated by the time the internal temperature of various meat preparations

reached 69C. Products tested included lymph nodes, blood clots and bone marrow. Frescura and co-workers (1976) found that SVDV was inactivated when the internal

temperature of a seasoned sausage reached 61C. Fresh samples of offal (liver, kidney, and lung) have been shown to be contaminated with viable SVDV (Frescura et al., 1976). There is no evidence that SVDV survival times in offal tissues are longer or shorter than in meat.

Therefore, it is assumed that SVDV is inactivated by heating to a core temperature of 70C for 30 minutes, and increasing temperature controls.

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16. APPENDIX 5: ASSESSING THE PROBABILITY OF CROSS CONTAMINATION BETWEEN SEGREGATED FEEDS

Currently certain restricted proteins are permitted in non-ruminant farm animal feed, such as fishmeal, but are banned in ruminant feed. Bakery and confectionary products containing certain products of animal origin, such as milk, fat, eggs and non-ruminant gelatine can also be used in farm animal feed. In the case that processed waste food was permitted in feed for pigs, poultry and fish, adequate segregation of feeds and sufficient sorting of materials by livestock species would have to be implemented to prevent intraspecies recycling (terrestrial animal species being feed the same species) and contamination of ruminant feed. Segregation of restricted proteins Under the TSE Regulations, there are currently strict separation measures required during production, storage, transport and on farm use to segregate ‘restricted proteins’ (and products containing them) and ruminant feed (& other non-target non-ruminant species in the case of feed for aquaculture animals) and also to prevent ruminant access (& access by other non-target non-ruminant species in the case of feed for aquaculture animals). These separation arrangements are required at:

Businesses manufacturing feed products including feedmills, feed blending plants, mobile mixers, home compounders.

Businesses storing and transporting particularly in bulk.

Farms where livestock are kept. This applies to the following materials here described as ‘restricted proteins’:

Fishmeal – commonly used in game bird rations and creep feed for poultry and pigs.

Fishmeal can be used in liquid milk replacers for young ruminant animals - used infrequently, or not at all in the UK.

Di and tri calcium phosphate of animal origin –used infrequently, or not at all in the UK.

Blood products of non-ruminant origin – very low level use in feed for farmed fish and pig weaner rations.

Processed animal protein of non-ruminant origin in feed for aquaculture animals - used infrequently, or not at all in the UK.

The controls for manufacture include physical separation through floor to ceiling partitions or using separate entirely enclosed production lines. Some feedmills seasonally clean down equipment to allow production of different compound feeds at different times of year. Time-separation between batches, through flushing of a production line with an inert batch of feed material is known to be unlikely to entirely remove material containing animal tissues from a production line, due to ‘hang-up’ areas, where materials and dust can accumulate. Stringent controls limit the ability of feedmills to make full use of the derogation, which allow for such dual stream production. From Table 17, it can be seen that only eight feedmills in 2006 and nine feedmills in 2012, have produced non-ruminant feed containing fishmeal in the same feedmill as ruminant feed and some of these have not been truly dual stream,

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adopting a seasonal clean-down to allow production of game bird feed containing fishmeal in the summer months. Table 17: Numbers of feedmills producing non-ruminant feed containing fishmeal

Year

AHVLA data for GB 2006 -12.

Total mills

Number dedicated to non-ruminant

Number producing

ruminant feed +/-non-

ruminant feed

Number using restricted protein in non-ruminant

feed only i.e. mainly fishmeal,

occasionally non-ruminant blood

products) in non-ruminant feed

production

Number using restricted protein in non-ruminant feed

in mills also producing ruminant feed on completely separate lines or using clean-down at end of season

2006 274 83 191 93 9 2012 281 65 216 68 8

Overall compliance with the requirements in the TSE and ABP regulations is generally high, within the feed industry. Figures from the National Feed Audit (NFA) database (shown in Table 18) support this assertion. The NFA is GB’s risk based inspection and sampling programme to support controls in the EU TSE and ABP Feed Bans, which cover businesses throughout the farm animal feed chain. An infraction in the tables provided constitutes either a breach in the regulations found at an inspection (procedural breach), such as inadequate separation between ruminant feed production and non-ruminant feed production using fishmeal or a sample test result which is in breach of the legislation (sampling breach), such as terrestrial animal bone fragments found in ruminant feed. Table 18: Number of procedural breaches found at inspection visits to farms and

feedmills in the NFA programme 2005-2012

Year Number of inspections

to farms

Total number of inspections at feed mills

Total number of inspections to all feed businesses

Total number of inspection visits

to farms with procedural breaches

Total number of inspection visits to

feedmills with procedural breaches

2005 1152 515 2036 18 5

2006 1134 715 2256 4 3

2007 930 549 1826 4 1

2008 1237 710 2322 2 2

2009 1618 580 2537 2 1

2010 1807 576 2691 1 1

2011 1582 596 2521 3 0

2012 1357 588 2254 1 1

Mean 1352 603 2305 4.3 1.75

Probability of breach

- - - 3.2 x 10-3

2.9 x 10-3

All feed samples are tested at the National Reference Laboratory, using Microscopic Analysis Testing (MAT). Other speciation testing, such as PCR, have been used to determine species or origin for positive results.

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Table 19: Number of sampling breaches found in feed materials, ruminant compound feeds and non-ruminant compound feeds samples tested in the NFA programme 2005-2012

Year

Total Feed materials sampled

Number of samples tested in breach of

the regulations

Total ruminant

compound feeds

sampled

Number of samples tested in

breach of the regulations

Total non-ruminant

compound feeds

sampled

Number of samples tested in

breach of the regulations

2005 4572 0 3932 20(fish) 4066 0 2006 6191 5 4430 9 3818 3 2007 3538 2 3284 5 2127 2 2008 3719 30* 4381 17* 1498 0 2009 3161 0 3292 2 1412 0 2010 1881 1 3290 1 1391 1 2011 1138 13** 3064 0 1197 3 2012 1472 20** 2927 3 993 0

Mean 3209 8.9 3575 7.1 2062 1.1

Probability of breach

- 2.8 x 10-3

- 2.0 x 10-3

- 5.3 x 10-4

* The high numbers of non-compliant samples in 2008 mainly relate to one incident involving an imported wheatfeed contaminated with out-of-date petfood.

** The high numbers of non-compliant feed samples in 2011/2012 mainly related to two incidents involving bakery waste containing meat products from food retail premises.

Figures shown in Table 19 are samples collected at portal stores, feedmills, intermediaries/stores, hauliers and on farm between 2005 and 2012. The feed materials sampled are mainly imported vegetable proteins and the ruminant and non-ruminant feeds sampled are finished feeds or concentrates manufactured in UK. Very few home produced feed materials are sampled. During the period 2005 to 2012, there have been on average 1,352 farm inspections per annum and a procedural breach has been found on average in 4.3 of those visits, which is equivalent to a probability of 3.2 x 10-3 breaches per inspection. During the same period on average 1.75 procedural breaches have been found in an average 603 inspection visits to feedmills per annum, which is equivalent to a probability of 2.9 x 10-3 breaches per inspection. During the period 2005 to 2012, there have been on average 3,209 feed materials sampled per annum, of which on average 8.9 were in breach of the regulations, which is equivalent to a probability of 2.8 x 10-3 breaches per sample. For ruminant compound feeds, there have been on average 3575 samples tested per annum, of which 7.1 were in breach of the regulations, which is equivalent to a probability of 2.0 x 10-3 breaches per sample. For non-ruminant compound feeds, there have been on average 2062 samples tested per annum, of which 1.1 were in breach of the regulations, which is equivalent to a probability of 5.3 x 10-4 breaches per sample. During the period there were three main incidents where contaminated feed had been distributed widely through the industry contributed to a high proportion of the total number of sample breaches. Also of relevance to the risk assessment is the compliance of the feed and farming industry with the TSE Feed Ban controls requiring separation during feed production, storage and on farm use of ruminant feed and ruminant access from non-ruminant feed containing fishmeal.

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Using the same time period and the same total number of inspections and samples collected, the following breaches in Tables 20 and 21 were identified. Table 20: Number of procedural breaches involving inadequate separation of ruminant

feed (&/or access) to non-ruminant feed containing fishmeal.

Feedmill

(production/ labelling)

Farm (storage)

Farm (deliberate

use)

Mobile Mixer

(mixing)

On farm mixer

(mixing) Transport Store

2005 1 3 3 2 8 1 2006 3 1 4 2007 1 1

2008 1 (Dual stream)

1

2009 1 1 2 1 2010 1 2011 2012

Total 8 4 3 4 14 2 1

Table 21: Number of samples, where fishmeal was detected in ruminant feed

Feedmill (production)

Farm (mixing, storage or use)

Import

2005 2 18 2006 2 2 2007 2008 1 2009 2010

2011 2012 Total 4 21 0

There have been 36 inspections where procedural breaches were found involving inadequate separation of fishmeal or feed containing fishmeal out of 18,443 inspections during the 8 year period between 2005 and 2012. This equates to a probability of 2.0 x10-3

breaches per inspection. There have been 25 samples where fish bone was detected in ruminant feed, as a result of use of fishmeal, in 54,272 samples of raw materials and ruminant compound feeds tested, during the same period. This equates to a probability of 4.6 x10-4 breaches per sample. The number of incidents involving inadequate separation of ruminant feed from non-ruminant feed containing fishmeal has reduced with time. Between the period 2009-2012, there have been 6 procedural breaches in 10,003 inspections. This equates to a probability of 6 x10-4

breaches per inspection where a procedural breach has been found and no samples where fish bones have been detected in ruminant feed following fishmeal use. This may have been

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due to increased awareness in the feed and farming industry as time from the ban on using fishmeal in ruminant feed increased, or it may have been due to reduced usage of fishmeal due to the increasing cost over the period. The ban originally came into force in 2001. Segregation of bakery products Bakery products (such as bread, cakes, pastry, biscuits), pasta, chocolate, sweets and similar products such as breakfast cereals can currently be used in farm animal feed which:

have undergone processing* as defined in Article 2 (1)(m) of Regulation (EC) No. 852/2004 (Hygiene of Foodstuffs) or in accordance with the Implementing Regulation. Under the Hygiene of Foodstuffs Regulation, ‘processing’ means any action that substantially alters the initial product, including heating, smoking, curing, maturing, drying, marinating, extraction, extrusion or a combination of those processes;

are composed of or contain one of the following Category 3 foodstuffs no longer intended for human consumption: milk*, milk-based products, milk-derived products, eggs*, egg products, honey, rendered fats, collagen and/or gelatine of non-ruminant origin. Foodstuffs containing rennet can also be used. and

do not contain, and have not been in contact with raw eggs, meat, fish, and products or preparations derived from or incorporating meat or fish.

in addition all necessary precautions must have been taken to prevent contamination of the material with products not eligible for feed use, such as meat, fish and products containing them.

*Most unbaked bread doughs are made from flour, water and yeast and do not contain products of animal origin. Unbaked doughs and raw pastries, which do contain products of animal origin are considered to have satisfied the processing requirement, if the product of animal origin included as an ingredient has been heat treated. This also applies to fillings and toppings. Single pasteurisation of milk and egg products would satisfy this requirement.

These can be sourced from manufacturing sources or retail premises and must not originate from or be stored in a household kitchen or catering sources such as restaurants, fast-food outlets, catering establishments etc. This is another area where separation controls are required. Control measures include a list of types of food product eligible for use in farm animal feed, ineligible for use in feed, but can go to landfill and food types, which must be disposed of or used as per Category 3 ABP requirements. This list has been generated by the Competent Authorities in GB.

Particular control requirements have been developed for such materials being sourced from supermarket stores via supermarket returns depots. Separation of eligible products begins at the store, where areas of the store from which products can be selected are identified, these are transported in colour-coded clear plastic bags in separate roll cages or boxes from store back to returns depot, where the bags are visually checked and then consigned to a compactor. A further visual and physical check then takes place at the receiving feed business, where bags are opened on a conveyor belt by operatives, who can quickly identify and reject ineligible items and material in contact with it. The operative can stop and clean and disinfect the belt down, before resuming operations. Identification on incoming bags means feedback can take place to the supplying supermarket retailer on stores, which are performing badly or on systems that are not functioning effectively.

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A recent inspection visit to a supermarket returns depot, where a separation system has been operating since 2011 confirmed that the feed business had found in the last month non-conforming meat products in bags that should only contain bakery waste. The non-conforming products included cooked meats, meat wraps, meat pasties, sausage rolls, pork pies and pepperami. This was equivalent to 0.5% by weight of the total tonnage of material sent to the feed business in the month, which had originated from supermarket stores in 10 county areas. Competent Authorities can also check on system quality. These systems, from AHVLA experience, observation and inspections in the last couple of years can be effective in preventing ineligible material entering the feed chain. Issues with lack of separation tend to occur at the start of the process. Control is reliant on a responsible feed operator, adopting a thorough checking and control system on entry into the feed operation. Feed-back systems are essential in trying to ensure better control higher up the system. Table 22: Feed incidents involving food no longer intended for human consumption

Feedmill (production) Farm (deliberate use)

2005 2006 2007 1

Biscuit-meal/ chocolate

2008 2009 2010 2011 1

Biscuit meal containing cooked meat from sandwich making shops

1 Chocolate biscuit/ ruminant

gelatine 2012 1

Biscuit meal containing chicken proteins in pasta mix

Total 3 1

Between 2005 and 2012 there have been 4 incidents found involving food waste materials out of 18,433 inspections. This equates to a probability of 2.17 x 10-4 breaches per inspection. Therefore there is a low probability of incidents occurring per sample as defined in the scope as rare, but does occur. The two incidents involving biscuit meal products in 2011 and in 2012 are worth considering further. The first incident involved returns from sandwich-making shops operating under a single business umbrella. The receiving feed business was entirely reliant on the food business to ensure that bakery returns were eligible for use in farm animal feed. Consignments arrived in bulk and there was no procedure available to thoroughly check product arriving. No audit was made of the food business. A significant proportion of the returned food waste should have been designated as catering waste and separation protocols had broken down leading to out-of-date cooked meat products entering the feed chain. In the second incident, a waste contractor sub-contracted the food waste to a feed business, which was accepting all food waste from the food business and sending ineligible product for alternative disposal. Pasta products coated with animal products of avian and porcine origin were inadvertently accepted as being acceptable for feed use.

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In both feed incidents, the biscuit meal products had been sent to feedmills manufacturing compound feed for farm animals. The incidents involved risk assessments to ascertain the likelihood of new notifiable disease or BSE cases resulting in exposed animals and significant tracing and testing activity to remove any remaining product from the farm animal feed chains. Conclusions on the probability of cross contamination between feed types The figures provided relate to incidents involving breaches of the TSE or ABP Feed ban controls caused through a lack of separation at different stages in the feed chain. If it was assumed that the implementation of the current controls for enforcement of separation would be the same for the separation of source waste food materials for animal feed, then it is likely that there would be a low probability of a breach event occurring during the year. From viewing the probability of segregation breaches in bakery waste and with fish meal, the lowest rate of segregation failure occurred with 25 samples of fish bone detected in 54,272 ruminant feed, equating to a probability of 4.6 x10-4 per sample. The maximum estimated probability of segregation failure occurred in on farm, with 4.3 breaches identified from 1,352 visits, which is equivalent to a probability of 3.2 x 10-3 breaches per inspection. When summing the total number of breaches and total samples/inspections, the average probability of failure was estimated to be 5.36 x10-4 per sample/inspection. When such events occur, the degree of cross-contamination of materials could be highly variable. The amount of material involved would depend on where in the process the contamination event occurred, the scale of the enterprise, and whether the event was a one off accident or a continuous failure to implement controls correctly. Given the time available with a theoretical process, no further quantification of this risk can be estimated. For cross contamination events between feed types, from Table 18, 20 and 21, it appears that the risk of cross contamination is more likely on farm than on other locations in the production chain. On farm events involve smaller volumes of feed fed to fewer animals, than events occurring higher up the sourcing chain. Further analysis of how new processes to ensure feed safety would be set up in practice would provide additional information. An increase in the degree of oversight of such processes by government agencies/standard setting bodies/industry associations and increased sampling may increase compliance and the understanding by operators of the importance of such controls. However, increasing controls would increase the costs of surveillance and EU and government thinking going forwards are now firmly pushing the responsibilities and costs back onto industry and increasing reliance on industry assurance schemes i.e. through ‘earned recognition’ and charging policies. Motivation to ensure effective controls are established is likely to be higher in the feed industry than in the food industry, where surplus foodstuffs are often considered a waste. Providing receiving feed businesses are motivated to deliver protocols that identify separation inadequacies to a high standard, these systems can be effective. However, if feed operators do not understand the significance of the controls and are prepared to take-short cuts to save money or operate sub-standard protocols, then control systems can fail. It may take a period of time for industry to adjust and to fully engage with all of the controls required for a new system. The requirement to separate fishmeal from ruminant feed came into force in the EU in 2001. In 2005 there were incidents involving the deliberate feeding of

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sheep with fishmeal and a number of incidents involving a lack of feed separation on farm involving mixing of non-ruminant feed containing fishmeal using the same equipment for mixing ruminant feed. In 2011/2012 there were no similar incidents. There have been more incidents on farms over the period, than in feedmills. During this period the cost of using fishmeal has risen from £350 per tonne, steadily up to £1320 per tonne and although prices subsequently fell, it had risen to above £1320 per tonne again by August 2012. Compliance may have improved due to increasing awareness in the feed and farming sector or to reduced use of fishmeal. Fishmeal is now mainly used in the creep feed and game sectors. If the end-product of processing is subsequently sold through one or more steps to larger feed manufacturers, then significant amounts of farm animal feed can be contaminated. At each further step of mixing, dilution occurs, but if the risk of new disease is high enough to warrant farm animal movement restrictions, then significant numbers of animals can be involved. If parts of the feed industry are closed down in order to prevent release of potentially contaminated product or to require cleaning and disinfection of equipment, this can have a significant effect on feed supply. If businesses fail in preventing feed contamination there can be major consequences for the feed and farming industry. APHA completes a risk assessment for all major incidents. Standard practice is currently to restrict, inspect and monitor farm animals, that have been exposed to catering waste containing or potentially contaminated with meat or meat products for a 21 day period following last access. Ruminants exposed to protein of ruminant origin are restricted until a risk assessment is completed to determine whether they will be allowed to enter the food chain in the future. As an example of the extent of distribution that may be involved and the large numbers of animals, which may be exposed, in 2008, an imported wheatfeed contaminated with petfood containing processed animal protein was incorporated into over 835 batches of compound feed for ruminants alone. Only 13 ruminant feed samples and 21 samples of wheat feed showed the presence of bone fragments or muscle fibres. Animal Health traced the samples of ruminant feed with confirmed bone fragments and/or muscle fibres to loads that went to 24 premises, some of which were agricultural stores or had no ruminants still present on the premises. This resulted in 6,860 sheep and 1,200 cattle having movement restrictions imposed on them, that had access to ruminant feed confirmed as containing wheat feed contaminated with bone fragments and muscle fibres on 17 premises.

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