With the sudden outbreak of bird ‘flu, the poultry industry is understandably on edge. There are at least eight farms under quarantine between Chilliwack and Abbotsford because of the highly contagious, high-pathogenic H5N2 virus.
This brings back nightmare memories of the 2004 outbreak of the high-path H7N3 which spread over 42 Fraser Valley farms and nearly a dozen backyard coups. Some 17 million chickens, turkeys and other domestic birds were slaughtered. The current outbreak is already having an economic sting especially with losses from the looming Christmas market. Some 155,000 birds have been or are being humanely slaughtered.
When diseased animals are ordered slaughtered by the Canadian Food Inspection Agency (CFIA) under the Health of Animals Act, compensation of loss is provided to farmers.
The CFIA undertook testing of infected birds at the National Centre for Foreign Animal Diseases and confirmed that the strain causing the current influenza outbreak is a highly-pathogenic H5N2 virus.
According to CFIA, H5N2 is a subtype known to affect both wild and domestic birds and the highly pathogenic strain causes severe illness and death, especially in poultry. The low-pathogenic strain of the virus causes less severe illness, lower egg production, and lower rates of mortality. It triggered outbreaks in B.C. in 2009 and Manitoba in 2010.
Avian influenza viruses are divided by subtypes based on two proteins found in the viruses. These are hemagglutinin, or “H” protein, and neuraminidase, or “N” protein. There are 16 H types and 9 N types which create a total 144 possible combinations. The CFIA stated on its website that the H5 and H7 subtypes of the virus are of particular concern, given their ability to mutate from low pathogenic to high pathogenic after they infect domestic birds. These two H-types have been known to cause serious disease or mortality in domestic poultry. Low pathogenic H5 and H7 viruses are quite common in wild waterfowl.
To try to prevent further spread, the CFIA has set up a primary control zone bordered on the west by the Pacific Ocean, on the south by the United States border, on the north by Highway 16, and on the east by the border between British Columbia and Alberta. Basically it sweeps across all of southern B.C. which has a high concentration of poultry operations.
All movement of domestic birds in, out, and around this zone is strictly controlled and requires a CFIA permit. This includes not only birds but poultry products and by-products and any material that has been in contact with captive birds. Both the province and poultry producers fully support the CFIA’s decision and they are all working in cooperation.
The poultry industry produces significant economic benefits for B.C. Including chicken and turkey producers, processors and satellite industries, the B.C. poultry industry generates about $2.4 billion in economic output contributing $712.4 million in GDP to BC’s economy. In 2011, there were 331 chicken farms in British Columbia producing about 154 million kilograms of meat and generating $351 million in farm cash receipts. Chicken producers contribute an estimated $37.9 million to total municipal, provincial, and federal taxes.
At least seven countries have imposed trade restrictions on B.C. poultry.
Where the virus came from is still under investigation but wild birds, especially waterfowl, are natural reservoirs of influenza viruses. They may not be affected by the disease but they can transmit it to domestic birds. Once in the barn, the disease can spread extremely quickly and without comprehensive biosecurity measures it can be spread through contaminated manure, litter, clothing, footwear, vehicles, equipment, feed and water.
Avian flu is not a risk to human food safety so long as all poultry is properly handled and cooked.