8/6/2019 THE CONTROL OF ANIMAL DISEASES IN EUROPE

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Introduction

1 The Society has been following the rapid spreadof Bluetongue disease in Europe with some concern.The spread of the disease has brought important issuesto the fore,particularly for countries like Scotland thatare currently disease free but share land borders and or trade with countries where the disease occurs. Itbelieves that it is now timely to take stock of current

animal disease control measure in Europe, and thepotential for vaccination to improve both animalwelfare and the economic health of the Europeanlivestock industry.

Background

2 Bluetongue disease is an infection of ruminant speciescaused by a virus of the Orbivirus genus of theReoviridae family, commonly referred to as bluetonguevirus (BTV).The virus is transmitted among animals bybiting midges of the Culicoides species. It has hithertobeen a tropical disease, and its spread into Europe

appears to have been encouraged by the effect of the

warming climate on the life cycle of the midges.Bluetongue viruses do not pose a risk to public health.Their impact is economic through loss of productivityand increased trade restrictions, while they alsoadversely affects animal welfare causing death andclinical signs including oral, respiratory, gastrointestinaland foot lesions among others.

3 The ruminant livestock sector is very important to

Scotland’s economy and to the sustainability of its ruralcommunities in particular. Figures from 2007 publishedby the Scottish Government1 show that the totalincome from farming in Scotland was £628M, withagriculture contributing 0.7% of GrossValue Added toScotland, higher than in any other part of the UK.The livestock sector and livestock products accountedfor £740M (28%) and £300M (11%) of the total grossoutput for agriculture. Even this underestimates theimportance of farming, which crucially underpins thesustainability of the economy, way of life andenvironment of many rural areas2.

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1 Scottish Government,Agr iculture Facts and Figures 2008 (http://www.scotland.gov.uk/Publications/2008/06/16141710/0)2 The Future of Scotland’s Hills and Islands, September 2008. (http://www.royalsoced.org.uk/enquiries/hill_and_island_areas/index.htm)

THE CONTROL OF ANIMAL DISEASES IN EUROPE

Summary

• EU: the RSE suggests that the EU Commission change the regulations to permit regions that are Bluetongue-free to be allowed to vaccinate with strain 8 Bluetongue vaccine without declaring themselvesProtection Zones – instead becoming ‘free of BTV8 with vaccine’.This could be applicable to other diseases (e.g. BTV 1,AHS,WNF) where vaccination is a recognised control option.We recommend that the EU Commission continues to review the movement of livestock (and zoo animals) across EU bordersand within EU member states in order that animal diseases such as Bluetongue are prevented from

impacting upon food production within the EU and across the world.We recommend that in “areas free of BTV8 with vaccine”, animals can only be imported when shown to be a) vaccinated and b) free 

  from infection.

The EU Commission should also be encouraged to fund the development of DIVAVaccines for diseaseswhich are now appearing in Southern Europe.

• GB: Scotland has the opportunity to adopt a compulsory vaccination scheme which should minimise the impact of Bluetongue disease. The RSE believes that DEFRA in England andWales should similarly adopt a compulsory vaccination scheme to enable GB to become Bluetongue free.

• Scotland: the Scottish Government should focus more research effort into the pathogenesis and persistence 

of diseases of livestock, such as Bluetongue. Short-term ‘emergency’ research projects must be backed upby investment in longer term research programmes.

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Spread of Bluetongue disease across Europe

4 Bluetongue disease can result from infection by 24different serotypes of BTV, with the serious outbreakin Northern Europe over recent years and the 2007incursion into South East England being caused byserotype 8 (BTV8) (See Figure 1).

5 Bluetongue was first described in South Africa buthas since been identified in a number of countries inthe tropics and sub-tropics3. Since 1999 there havebeen a number of outbreaks of Bluetongue in Europe,which have been well north and west of its normal

distribution.It appears that the virus has spread fromboth Turkey and North Africa (see Figure 2).

Control of Bluetongue disease in Scotland

6 Like many other diseases, susceptible animals may beprotected by vaccination.Where vaccination againstBluetongue disease is carried out in regions free fromdisease,the region must be declared a ProtectionZone.This regulation was, however, developed whenvaccination required the use of a live vaccine, withthe consequent risks of infection. Current vaccines

now use a dead virus,without these risks.

7 While the risk of Bluetongue disease reaching

Scotland is considered low, it is recognised that thedisease incidence in England may increase rapidly

and that the current Restricted (presence of clinical

cases) and Protection Zones will continue to expand

in line with the voluntary vaccination programme

in England. A close watch is kept on disease

developments.Advice on when and where to

vaccinate is given to Scottish Ministers by Scotland’s

ChiefVeterinary Officer in consultation with industry

stakeholders and the scientific community.

8 The currently agreed view is that vaccination in

Scotland should take place during the next vector-free

period and vaccine orders have now been secured by

the Scottish Government. The Scottish farming

community also strongly supports the introduction

of an effective vaccination policy given that there are

significant trade implications for the export of 

unvaccinated,and therefore susceptible, animals into

endemic areas, were the majority of Scotland’s export

market continues to be, even though Scotland remains

free of the disease.

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3 http://www.oie.int/wahid-prod/public.php?page=disease

Figure 1: Distribution of Bluetongue disease restriction zones across Europe Source:EU Commission

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9 From a GB perspective of planning to control

livestock diseases, ideally a single strategy for Bluetongue disease control would be designed,as the landmass of England,Wales and Scotlandshould be treated as single epidemiological unit.At the present time, a compulsory vaccination schemeis considered the optimal method of control,and possibly in future eradication of Bluetonguedisease,and Scotland has the opportunity to takethis considered approach which should minimisethe impact of Bluetongue disease on both theScottish economy and on the livestock themselves.The RSE believes that the Department of the

Environment, Food and Rural Affairs in Englandand Wales should similarly adopt a compulsoryvaccination scheme to enable Great Britain tobecome Bluetongue free.

 EU rules for vaccination and imports

10 The European Commission currently forbidsBluetongue vaccination for BTV8 in a Bluetongue-free country or region, unless that country or regiondeclares itself to be a Protection Zone.ProtectionZones, however,allow the movement of animals intothat zone from all other Protection Zones with the

same serotype across Europe.The decision to

vaccinate will, therefore, result in a country losing its

Bluetongue disease-free status and becoming aProtection zone, thus allowing movement of animalsfrom other Protection Zones within and between EUMember States and resulting in increased risk of disease incursion.This has a serious consequencefor a country, like Scotland, free from the diseaseand not vaccinating, but neighbouring a country,which may or may not have infected animals ata significant prevalence that has implemented avoluntary vaccination strategy. The risk of infectedanimals moving into the disease free country issignificantly increased, effectively forcing its hand to

implement a vaccination policy, which has theperverse effect of easing the movement of potentiallyinfected animals (and the pathogen) into the country,and contributing to its spread across Europe.

11 The RSE believes that it is now very timely to reviewthe European approach to such exotic diseases, partlybecause of the development of inactivated vaccinessince introduction of the current regulations, andpartly because of the potential for further exoticdiseases,such as BTV1,African Horse Sickness (AHS)and West Nile Fever (WNF), to sweep through

Europe, facilitated by climatic and other changes.

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Figure 2: Bluetongue virus introductions into Europe Source:Peter Mertens, Institute for Animal Health; Note: the different colours represent the different serotypes of the Bluetongue virus

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12 In this new context,not withstanding the economicfactors, consideration should be given tostrengthening the procedures and changing theregulations in order to further reduce the spread

of viral pathogens.An effective way forward would befor the EU Commission to change the regulations topermit regions that are Bluetongue-free to be allowedto vaccinate with strain 8 Bluetongue vaccine withoutdeclaring themselves Protection Zones, but insteadbecoming‘free of BTV8 with vaccine’.In this zone,animals could only be imported when shown to be a)vaccinated and b) free from infection. Not only wouldthis be a sound science- based policy, it would notrestrict countries in the new category from exportingto countries in which the disease was endemic.

13 It is important to recognise that these considerationscould be applicable to other diseases (e.g. BTV 1,AHS,WNF) where vaccination is a recognised controloption.They would be of particular relevance wherevaccines are untested in their field efficacy and wheremarker vaccines are not available, making it difficultto distinguish between infected and vaccinated andvaccinated/infected animals.To minimise spread of any infection, animals moving into the“free withvaccine” zones would be tested for viraemia andidentified using appropriate technologies.

14 We recommend that the EU Commission continues

to review the movement of livestock (and zooanimals) across EU borders and within EU member states in order that animal diseases such as Bluetongueare prevented from impacting upon food productionwithin the EU and across the world.This will becomeincreasingly important as Climate Change increases

the range of animal diseases to which Europeis subject.

Future research

15 In light of current concerns over food security, theScottish Government should focus more researcheffort into the pathogenesis and persistence of diseasesof livestock, such as Bluetongue, and in this context,the RSE welcomes the Scottish Government’srecently commissioned research projects into better understanding the epidemiology of Bluetonguedisease in relation to the midge vector species.There is a dearth of knowledge on diseasepathogenesis of BTV8 in temperate countries whereanimals have not previously been exposed to thisvirus.It is likely that longer term studies on thesusceptibility of different animal species to BTV,the possible persistence of the virus in the host species,and the dynamics of disease transmission will require

detailed investigation in the future.Short-term‘emergency’ research projects must,however,bebacked up by investment in longer term researchprogrammes.The EU Commission should also beencouraged to fund the development of DIVA(Differentiating Infected fromVaccinated Animals)Vaccines for diseases which are now appearing inSouthern Europe.

Additional Information

16 Copies of this Statement and others that the

RSE has produced, including the RSE Inquiryinto Foot and Mouth Disease in Scotland (2002);The Scientific Issues Surrounding the Controlof Infectious Salmon Anaemia (ISA) in Scotland(2002); and Avian Influenza:An Assessment of theThreat to Scotland (2007), can be requested fromthe RSE (email: evidenceadvice@royalsoced.org.uk).Responses are also published on the RSE website(www.royalsoced.org.uk).

The Royal Society of Edinburgh (RSE) is Scotland’s National Academy. It is an independent body with a

multidisciplinary fellowship of men and women of international standing which makes it uniquely placed to

offer informed, independent comment on matters of national interest.

The Royal Society of Edinburgh, Scotland's National Academy, is Scottish Charity No. SC000470

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