U.S. avian influenza outbreaks are threatening to shut down U.S. exports of chicken, turkey, eggs and poultry genetic breeding stock unless the disease is stamped out and trading partners begin abiding by international zoning guidelines for trade bans.
As outbreaks of the H5N2 highly pathogenic avian influenza virus have spread to 14 U.S. states so far, the list of countries restricting U.S. poultry exports because of the disease has grown.
At stake are over $5.8 billion in U.S. poultry exports in 2014, representing 20.6 percent of the industry’s production of broilers, 13.8 percent of turkeys and 4.9 percent of eggs.
Jim Sumner, president of USA Poultry & Egg Export Council, said trade restrictions by 40 countries have already cost U.S. poultry and egg producers $600 million in the first three months of this year.
However, the entire world has much at stake in food security and trade interests in the ongoing avian influenza epizootics worldwide.
Vaccination for highly pathogenic avian influenza proposed
The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) has proposed a vaccination program to combat the continuing spread of the highly pathogenic H5N2 in commercial poultry in five U.S. states.
U.S. poultry and egg producers and other stakeholders have until May 15 to comment on the proposal to vaccinate commercial poultry in the five states as part of a strategy to eradicate the highly pathogenic avian influenza.
A primary concern among the U.S. poultry industry is the probable implications of a vaccination program for U.S. exports of poultry meat, eggs and breeding stock. Many countries, including the U.S., restrict poultry imports based on a country’s use of avian influenza vaccination programs.
The chief criticism of the use of vaccination programs around the world has been that they sometimes have been too much of a standalone tool for the control of highly pathogenic avian influenza and not part of a comprehensive eradication strategy. Use of vaccination, without proper monitoring and commitment to the stamping out of the disease, can lead to the vaccination’s masking of continued avian influenza infection and the shedding of the disease in the environment.
APHIS officials are working with U.S. poultry producers and other experts to devise a comprehensive eradication strategy that, if adopted, would include the use of vaccination. In preliminary discussions with the poultry industry producers, they have said any plan must include provisions such as the monitoring infections (using rapid detection such as PCR) and a clear exit strategy.
35 high-path avian influenza events and counting
The highly pathogenic avian influenza outbreaks in the U.S. and the vaccination program now being formulated to be properly understood should be viewed in the context of outbreaks and control strategies used around the world in recent decades.
There have been 35 high-pathogenic avian influenza disease events since 1959, according to data published by Dr. David Swayne, USDA Agricultural Research Service. The data show three high-pathogenic avian influenza disease epizootics in the 1960s, three such events in the 1970s, three in the 1980s, and since then a dramatic rise in the number of the these epizootics:
- Eight highly pathogenic avian influenza epizootics occurred in the 1990s
- 11 HPAI epizootics from 2000 to 2009
- Six HPAI epizootics from 2011 to the present time
The largest high-pathogenic avian influenza epizootic in 50 years started in 1996 and continues today. In fact, the current H5N2 epizootic in the U.S. and Canada is part of it. It is referred to as the Eurasia/Africa H5N1 epizootic, which includes re-assorted strains of H5N2, H5N3, H5N5, H5N6 and H5N8.
The number of doses of avian influenza vaccine manufactured and administered to combat this epizootic has skyrocketed in recent years without these avian influenza outbreaks being stamped out. This fact alone perhaps explains some of the skepticism over how vaccination has been employed around the world in avian influenza epizootics, especially in China.
However, experts say the problem is not with vaccination, per se, as a tool in an overall avian influenza eradication strategy, but with overdependence on vaccination where eradication efforts are poorly designed and executed or absent.
World needs to shift paradigms for avian influenza control
U.S. and world poultry producers are at a crossroads on biosecurity, avian influenza vaccinations and poultry trade as the result of ongoing highly pathogenic avian influenza outbreaks.
Following is a proposed beginning path forward for the world’s poultry industries in the battle with avian influenza:
- Abide by World Organization for Animal Health (OIE) guidelines when imposing trade restrictions on poultry meat and breeding stock.
- Adopt and abide by compartmentalization zones for trade, especially for poultry breeding stock.
- Cease excluding poultry imports solely on the basis that vaccination is employed somewhere within the exporting country’s borders.
With the current widespread and elevated level of highly pathogenic avian influenza virus in wild fowl around the world and in poultry flocks in more countries, new and more widely-adhered-to veterinary and trade protocols are necessary. Otherwise, highly pathogenic avian influenza will continue to proliferate, while trade flounders.
