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We Must Not Take EU and Asian HPAI Lightly

  

Dec 2, 2016

    

With the deteriorating HPAI situation in Asia and the EU, the U.S. industry should look to its defenses against introduction of AI virus onto commercial farms.  The events in the EU over past weeks closely follow the pattern of infection in 2014 with sporadic outbreaks resulting from direct and indirect contact between commercial flocks and migratory waterfowl and other free-living birds which carry virus and which is shed into the environment. 

In anticipation of a 2016 introduction, a consortium of state and federal wildlife biologists in cooperation with USDA-APHIS and ARS are conducting surveillance on hunter-killed ducks and dead birds collected in areas where migratory species congregate.  It is anticipated that over 35,000 birds will be sampled in fiscal 2016.

Initial reports confirm that outbreaks in Korea and Japan are caused by H5N6 HPAI.  All of the outbreaks in India, Israel and now twelve European nations are caused by H5N8 virus which has close similarities to the infective agent responsible for mortality in Asia in 2014.

Given that it is highly probable that virus will be introduced into the lower 48 states through one of the four flyways, biosecurity should be intensified. All of the poultry associations, the USDA, Land-Grant universities and extension personnel have written extensively on biosecurity procedures to limit introduction of infection.  Most of these recommendations involve the lowest tier of biosecurity which may or may not be effective, given deficiencies in physical facilities and the possible routes of infection.

 

Essentially biosecurity should be viewed as a pyramid. The highest tier is represented by Conceptual Biosecurity.  This relates to the relative position of farms and complexes, proximity to flyways and major roads and the movement and concentration of poultry in a given area. Unfortunately the deficiencies at this level cannot be changed but intensification of the succeeding tiers of biosecurity can compensate from inherent high risk.

The second tier comprises Structural Biosecurity which requires capital investment in facilities to allow for effective biosecurity procedures.  These include fencing, hardened road surfaces, efficient vehicle wash installations and modules to allow changing and showering of personnel before entry to the designated biosecure area surrounding poultry houses.

The third tier involves Operational Biosecurity comprising the routine procedures involving entry of personnel and vehicles to the biosecure area, decontamination, movement of live birds and products and their routing to and from central facilities including packing plants and feed mills.

Following the devastating epornitic in the upper Midwest in 2015, many integrators and farmers upgraded biosecurity.  The extent of their efforts as observed this year vary widely. Some operations simply pay lip service to recommendations with minimal effort to reduce risk of introducing infection. The more progressive operations have undergone a major phase-shift by developing a culture of biosecurity matched by extensive capital investment in facilities and installations. These are designed to limit the possibility of introduction of infection by personnel, vehicles and products through intensive Operational Biosecurity with written procedures, training, supervision and auditing.

Experience has shown that our industry has a short memory.  Biosecurity was a serious consideration after the 1984 outbreak of H5N1 HPAI in Pennsylvania and adjoining states.  Within two years there was an obvious decline in intensity at the operational level and there was very little to show in the form of improvements in structural biosecurity.  In contrast, the magnitude of losses in 2015 motivated investments to upgrade facilities. 

The amount which can be expended on biosecurity is a function of risk of introduction of infection, the effectiveness of the biosecurity precaution and the magnitude of losses subsequent to introduction of infection.  In the case of HPAI losses arise not only from depletion of the flock, (hopefully compensated for with Federal indemnity) and decontamination but consequential losses resulting from decreased output during restocking, loss of goodwill and other factors add to the cost of infection.

EGG-CITE has previously posted calculations which can be performed to demonstrate the return on expenditure on biosecurity and the relationship between risk factors and investment to minimize losses. If there are deficiencies in Structural or Operational Biosecurity now would be the time to reevaluate the susceptibility of operations to possible introduction of infection and to effect improvements.

From visits to egg production operations throughout the U.S. it is evident that there is a wide standard of compliance with accepted principles of biosecurity.  It is noted that in the EU during 2014 and 2015, despite individual farm outbreaks, costs accruing to the egg production industry were relatively minimal.  This is in part due to the fact that there are no ultra-large in-line units such as those that were affected in the Midwest in 2015. The preemptive planning in the EU, based on previous epornitics involved rapid diagnosis followed by elimination and disposal of small flocks within 24 hours which reduced lateral spread to other commercial farms. The experience gained in the U.S. during 2015 was applied to the January 2016 outbreak in Indiana which was restricted to the index farm and nine contact premises achieving rapid eradication.

It is anticipated that in the event that HPAI is introduced to the U.S. in 2017 that the lessons we have learned will be applied to minimize losses.  Carbon dioxide foam can be used to deplete floor-housed flocks given appropriate logistics support. Ventilation Shut-Down will be employed for caged flocks, some of which now exceed 350,000 hens in a single building. The problem with carcass disposal is still not resolved in many areas and the long-term prospects for Federal indemnity cannot be taken for granted.  Policy relating to vaccination in the face of a serious outbreak has yet to be resolved. In addition to the technical problems we will be faced with a new Administration although we hope that experienced and seasoned professionals in USDA-APHIS will be given the latitude they need to effectively counter both limited and extensive outbreaks. 

The resources of the Federal government and states should however be supported by individual efforts by all producers and contractors to make every effort to eliminate possible direct and indirect contact between free-living birds which serve as carriers and our flocks, all of which should be confined to bird-proof buildings. In the event that a flock is infected, effective biosecurity at the Structural and Operational levels will be required to prevent inter-farm dissemination of HPAI virus. Given that flocks are infectious before demonstrating clinical signs or mortality, constant vigilance and conformity to high standards of Operational Biosecurity are required.