Avian Influenza Monitoring and surveillance in The Netherlands

Ruth Bouwstra DVM PhD

GD Animal Health

The Netherlands

The Netherlands; such a small country

Exporting country: products

Export products from agri-food industry

Holland Worldwide:

Second largest exporter of agri

food products. Export value agri

food products: €94 billion. This is 22%

of the total export.

Holland…

..used to strict production rules and

regulations

4,3 million cows 12,4 million pigs

90 million poultry (>500 million slaughters)

17 million

The Netherlands

Monitoring animal health in Holland:

Objectives: •  Early identification of outbreaks •  Identification of new diseases

and infectious agents •  Awareness of trends and

developments in animal health and diseases

•  Virus •  Family Orthomyxoviridae

–  Three types of influenza A, B and C •  A lot of species •  B human seal •  C human

–  8 gen segments

Avian Influenza

Electron microscope

8 RNA segments

Haemagglutinine

Neuraminidase

Matrix proteine

Nucleoproteine

Influenza virus

Reservoir of Avian Influenza

•  H1-18 & N1-11

•  All combinations of H and N

•  More than 100 combinations

•  H1N1, H2N2, H3N2 human

•  H1N1, H1N2, H3N2 pigs

•  H3N8 en H7N7 horses

•  All subtypes birds

Pandemic: how could it happen?

Pluimvee

Low pathogenic or high pathogenic H5 en H7

Outbreak 2003

Dutch experience with AI Gelderland

Central area

Limburg

Southwest area

•  First report on 28/02/2003 in poultry-dense area in Gelderland

•  Ban on transport and culling started on 01/03

•  Transmission to farms out of infected area despite control measures (25/03)

•  Transmission to poultry-dense area in Limburg (03/04)

•  End of outbreak on 7/05 •  Total of 255 farms infected, over

30 million birds culled •  Transmitted to 89 persons, 1 died

Bataille et al., 2011

H7N7 HPAI 2003

Leasons learned of HPAI outbreak in 2003

•  Influenza viruses are to stay in wild birds •  Risk factors

–  High density is risk factor –  Free range farms

•  Early diagnosis in required

EU rules according control AI

Member States EU 1. shall carry out surveillance programmes in order to detect subtypes H5 and H7 in different species of poultry; 2. Cull H5 or H7 virus positive farms (risk for HPAI)

Focus on H5/H7 Poultry industry

Avian Influenza prevention, monitoring and diagnosis in the Netherlands

•  Syndromic surveillance –  Acute infections mainly of HPAI –  LPAI infections that cause mild disease

•  Early warning

•  Monitoring programme –  Detection of LPAI introductions that remain subclinical

Syndromic surveillance

•  Increased mortality more than 1-5% per day •  Reduction of egg production more than 5-10% •  Reduction in water and feed intake •  Sample submission to laboratory to exclude AI

–  Notify veterinary services –  AI in differential diagnosis -> direct submission to CVI

Early warning system

•  Some clinical signs but not likely caused by AI •  Practitioner or Animal Health Service •  Sample submission to laboratory to exclude AI

•  Main difference with syndromic surveillance –  No consequences for the farm –  Exclusion diagnostics

Monitoring programme; unique dataset

We do a lot more than required by the EU •  All poultry is tested at least once a year, except •  Free range chickens: 4 times per year •  Turkeys: every production cycle (2/3 per year) •  30 samples/farm are tested at the Dutch Animal Health

Service using the Idexx MultiS-Screen Ab ELISA test •  Positive samples are confirmed at CVI-WUR using

haemagglutination inhibition test –  sera are tested in HI using H5 and H7 antigens

Open scoop approach

GD •  ELISA •  If +

CVI •  HI H5 H7 •  If -

CVI •  Protein Array •  All subtypes

Virus Antibody

CVI • M PCR •  If +

CVI • H5 H7 rec PCR •  If -

CVI • HA NA typing • All subtypes

Diagnostics continues until subtype is known Food and Safety authority informs public health organization

Number of serious LPAI introductions (H1tm16)

YEAR   H5 H7   Total H5 H7   Remain   Total  virus   ab  

2006   1   1   2   2   4  2007   0   2   2   11   13  2008   0   5   5   5   10  2009   0   1   1   10   11  2010   1   3   4   16   20  2011   4   6   10   28   38  2012   2   0   2   28   30  2013   6   3   9   21   30  2014   2   9   11   31   42  2015   3   2  Total   19   30   46   152   200  

Oubreak 2014

5: 29-11 ● ● 1: 14-11

● 3&4: 19&20-11

● 2: 19-11

1. Hekendorp

2. Ter Aar

3. Kamperveen

4. Kamperveen

5. Zoeterwoude

Spread of the virus?

•  Contact tracing showed no indications for connections between outbreaks in Asia, Germany, the United Kingdom and the Netherlands.

•  No links between the 5 cases in the Netherlands. •  Important for preventive measurers

Question

•  Were the outbreaks on the five Dutch poultry farms caused by separate virus introductions or by transmission between farms?

THEREFORE THE AIM OF THE STUDY

•  Unravel possible routes of transmission of the Dutch HPAI H5N8 virus by sequence and temporal phylogenetic analysis.

MJ Network five Dutch H5N8 sequences.

•  Sequence differences were small

•  All 5 sequences derive from one or more virtual precursors and are not descendants of each other

54

2

3

1

1.  Hekendorp

2.  Ter Aar

3.  Kamperveen

4.  Kamperveen

5.  Zoeterwoude

Phylogenetic tree of H5N8 viruses

§  Origin of the H5N8 viruses occurred between 9 September 2007 and 20 June 2008

§  The common ancestor of European and Chiba isolates was estimated to have emerged somewhere between 15 July and 8 August 2014 (mean 28 July).

§  Four of the five Dutch strains were differently located in lineage I. Both viruses of Kamperveen diverted only in the first week of November consistent with the possible transmission between both

1

2

3 4

51.  Hekendorp

2.  Ter Aar

3.  Kamperveen

4.  Kamperveen

5.  Zoeterwoude 07 2008 2009 2010 2011 2012 2013 2014 2015

Transmission routes

5: 29-11 ● ● 1: 14-11

● 3&4: 19&20-11

● 2: 19-11

1. Hekendorp

2.  Ter Aar

3.  Kamperveen

4.  Kamperveen

5.  Zoeterwoude

•  4 separate introductions •  1 between-farm transmission

located 550 m from each other

The numbers tell the story

RR LPAI per poultry type 2007-2013

Type of poultry farms RR 95% CI P

Layer indoor 1.0

Layer outdoor 7.7 5.9 – 10.1 < 0.00001

Meat Turkey 8.5 5.6 – 13.0 < 0.00001

Turkey breeder 17.1 3.2 – 89.1 0.0001

Meat duck 12.1 6.9 – 21.0 < 0.00001

Duck breeder 43.9 23.2 – 83.2 < 0.00001

RR outdoor farms per year 2007-2013

LPAI introductions indoor and outdoor

RR LPAI per poultry type 2011-2013

Type of poultry farms RR 95% btbh P

Layer indoor 1.0

Layer outdoor 9.2 6.0 – 14.1 < 0.0001

Layer breeder 0.2 0.02 – 1.44 0.11

Meat turkey 12.9 6.9 – 24.3 < 0.0001

Duck breeder 25.6 8.5 – 77.1 < 0.0001

Conclusion

1)  2007-2013: every year higher RR in outdoor layer farms, farms with turkeys and ducks;

2)  RR LPAI increases over time on outdoor layer farms 3)  RR broiler in 2009: 0.2 4)  RR layer breeder: 0.2; higher biosecurity 5)  Possible risk factors

–  Free ranging –  Inadequate biosecurity –  Some species seem to be more susceptible

Conclusion

•  Differences in the RR of LPAI introduction per type of poultry farm and over time could be used to (re)design a targeted risk-based surveillance programme and to reconsider additional preventive measures.

Thanks for your attention!

Questions? r.bouwstra@gddiergezondheid.nl