neutralizing risks instead of stamping-out

Neutralizing risks instead of Stamping-Out

Harm KiezebrinkAssociate Research Fellow

Research Institute for Animal Welfare & Animal Husbandry

Friedrich Loeffler Institut Celle, Germany

© 2015 Applied Veterinary Technologies Europe AB

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• Contact between migratory birds and poultry• Wind-borne spreading between farms, via dust

and feathers• Absence of bio security protection at the farm

level• Contact between humans and infected birds

Pathways for transmission


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• “Estimating the Per-Contact Probability of Infection by Highly Pathogenic Avian Influenza (H7N7) Virus during the 2003 Epidemic in The Netherlands” (2012)

• “Avian influenza transmission risks: Analysis of biosecurity measures and contact structure in Dutch poultry farming” (September 2012)

• “Modelling the Wind-Borne Spread of Highly Pathogenic Avian Influenza Virus between Farms” (February 2012)

• “Genetic Data Provide Evidence for Wind-Mediated Transmission of Highly Pathogenic Avian Influenza” (March 2013)

Wageningen University is leading in researchon spreading of avian Influenza transmission:


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What happened in Hollandduring the outbreak of H7N7,

March 2003?• 270 million Euro direct costs

• 29 786 804 birds culled

• 1.134 farms• € 238.000/ farm; €

9,31/ bird 5.4%10.7%

72.8%

11.2%InfectedSus-pectedPre-ventiveWelfare


85%

15%

Infected poultry species

ChickensTurkeysMixed poultry


3%

97%

Infections under small farming (free range)

and hobby farming

Infected/suspected Preventive



and hobby farming

23%

68%

9%

Infected farm type

ChickensTurkeysMixed poultry



and hobby farming

79.2%12.0%8.7%

Type of farms infected during the H7N7 outbreak in Holland

Labor-intensive farms (Layers/parent stock)Labor-extensive farms (broiler/breeders)Turkey farms


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All current culling techniques were developed during the outbreak in Holland without prior testing:

• Stable gassing with CO2 en CO

• Container gassing• Electrocution (waterbath method)

Because of its labor intensity, large-scale culling most likely contributed to the intensity of the outbreak Responders became spreaders of the virus: 50% of all responders showed antibodies and most likely became carrier of the virus

Large-scale culling contributed to the spreading


Each farm type needs aspecific culling method

Labour intensive farms were culled using container gassing and electrocution Layers Biological farms (Grand)Parent stock Breeders Ducks Labour extensive farms were culled by stable gassing Turkeys Broilers Pullets


All culling methods are extremely labour intensive

Poultry was caught or taken out of the cage by hand and carried out to the culling equipment outside the house

Large packages of gas bottles, containers, power generators, frond loaders etc., needed to be in place before the culling procedure could start

In case of stable gassing, large numbers of responders needed to enter the infected house and take out the carcasses and bring these to the disposal containers


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Labour intensive farms are extremely vulnerable to get infected

• 4 727 124 of in total 29 370 427 birds were infected/suspected

• More than 79% of all farms with the notification Infected/suspected were labour intensive farms, indicating that poultry workers were most likely responsible for the infection of the flocks, due to the lack of following strict bio security protocols

• Only 12% of labour-extensive farms with young birds got infected, indicating that farms with a high-level of bio security and limited contact between humans and poultry are better protected against infections

• Only 3% of the small Free range and hobby farms got infected, indicating that direct contact between migratory birds and poultry plays only a marginal role

We do know that animal-to-human contact is the key transmitter of the infection


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To summarize

1. Layer farms and turkey farms are extremely at risk

2. More than 79% of all farms with the notification Infected/suspected were labour intensive farms, indicating that poultry workers were most likely responsible for the infection of the flocks, due to the lack of following strict bio security protocols

3. Only 12% of labour-extensive farms with young birds got infected, indicating that farms with a high-level of bio security and limited contact between humans and poultry are better protected against infections

4. Only 3% of the small Free range and hobby farms got infected, indicating that direct contact between migratory birds and poultry plays only a marginal role


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To summarize

5. Depopulation of broiler farms and hobby farms around infected layer farms turned out to be a destruction of resources

6. Complex culling methods are extremely costly

7. Stamping-out as a strategy is ineffective

8. Stamping-out caused distribution and spreading of the virus


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What happened in Iowaduring AI outbreak in the USA

spring 2015?


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Stamp it out!Within 24 hours:

Kill all animals Destruction all carcasses Clean and disinfect the establishments


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Stamp it out! 71 farms were infected, of witch 35 caged

layer farms 33.1 million birds were killed, of witch 32

million layers were caged layers average layer farm-size is 913.000 layers Total costs in Iowa: 1 billion USD (total

costs USA 8 billion USD $ 27,4 million per layer farm/ $30 per

layer


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Stamp it out! Approx. 1,000 to 1,500 workers involved

with Stamping- Out activities per farm Total costs in Iowa: 1 billion USD (total costs

USA 8 billion USD Loss of nearly 8,500 jobs Nearly $427 million in lost additional value,

more than half of which is income

Per layer farm, in average 1.188 tons of carcasses (average weight 1,3 kg/layer) were disposed


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Complete failure of Stamping out strategy

Per September 18, 2015: Ventilation Shutdown method is allowed in the USA

Emergency response by the flip of a switch

Unprecedented financial Government support for the poultry industry

breach of OIE Terrestrial Code

Economic advantage for the US poultry industry on the international market

Total defeat for animal welfare friendly production


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Concentrate on the different drivers• Introduction of the infection into the farm• Onward-spread between farms

• Transmission through contact structure between farms

• Wind-mediated spread • Transmission via rodents and farm dogs

Neutralize the risks of spreading• Isolate risks• Avoid direct contact• Avoid large scale operations

Emergency Response on a National level:Focus on epidemiology and the risks of spreading


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• Seal off the area completely and isolate all who are living/working on the farm

• Reduce number of responders to an absolute minimum and if possible, use the farmers’ own labour force to depopulate the farm

• Prevent contact between responders and infected birds, carcasses and contaminated materials as much as possible

• Neutralize virus loads on carcasses before handling

• Avoid the use complex culling & disposal techniques

Focus on Neutralising infection/contamination risks


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• Create a farm-based emergency response plan • Make an inventory of all possible transmission

routes• Possible introduction routes• Possible contamination risks• Possible routes for further spreading

• Use this plan as the basis for the farms’ bio security plan

• Define what would be the most appropriate culling & disposal technique

• Compensate and reward animal owners and farmers based on their active involvement

Emergency Response on local level:Focus on active involvement of animal owner and farmer


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Neutralize risks instead of stamping-out

neutralizing risks instead of stamping-out

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