Some of these birds have died from the deadly H5N2 avian influenza. Although this avian flu poses little risk to people, it is highly contagious to domestic poultry. To prevent the disease’s spread, the remaining birds were destroyed. Infected wild duck contact is suspected to have caused the outbreak.
Meanwhile, scientists are working to determine if the Tri-Cities outbreak was caused by the same H5N2 virus that was responsible for an outbreak in southwest British Columbia in December that resulted nearly 250,000 chickens and turkeys being culled. Although it’s the same strain, authorities won’t know if it’s the same virus without genetic testing, said a spokesman for the Washington Department of Agriculture (WDA).
Within two days, avian flu had killed 50 to 60 birds in a large backyard flock in Benton County. A second backyard flock received ducks from the first operation before the infection was discovered, spreading the virus.
The disease is transmitted through contact with feces from infected birds. Waterfowl can carry the disease but may not get sick themselves. Authorities are concerned this is one way the virus is spreading.
Federal researchers worked with hunters last week at the McNary National Wildlife Refuge east of the Tri-Cities testing geese and ducks for avian flu.
After a northern pintail duck in Whatcom County tested positive for H5N2 avian influenza in December, earlier testing of wild birds had focused on Western Washington. The H5N2 strain contains gene segments both from a deadly Eurasian avian flu and avian flu more typically found in North America. The detection in the pintail duck was the first time the H5N2 strain had been discovered in Washington, and the Tri-Cities outbreak was the first detection in the state’s domestic poultry, the WDA spokesman said.
As a result, a quarantine of at least 240 days for a 20-mile zone around the Tri-Cities properties with the infected flocks was quickly ordered by the state Department of Agriculture. This prohibits the movement of eggs, poultry and other poultry products outside of the quarantine zone. More testing of domestic flocks is planned for that area.
Last week, the Canadian government banned bird, raw poultry and poultry-products imports from Washington and Oregon. In addition to the Tri-Cities outbreak, a different avian flu virus was discovered last month in a backyard flock in southern Oregon. Officials insist there is no public health threat as avian flu does not affect meat or eggs; they remain safe to eat.
But concerns remain about wild birds spreading the virus. Given the growing popularity of raising backyard chickens, the recent outbreak is something small producers and hobby farmers should be aware of. The Department of Agriculture recommends poultry owners limit visits by outsiders to their chicken coops, or use a disinfectant on visitors’ boots, to reduce the risk of spreading infection.
As a result of these detections, some countries, including China, have placed a ban on imports of US poultry and egg products. But last December, the US Department Agriculture addressed these finds in an attempt to prevent concerned trading partners from overreacting.
“USDA is in communication with trading partners to provide more information on the detections of avian influenza in Oregon and Washington State,” the agency said in a statement. “We are also sharing information on our strong surveillance for avian influenza, which has not detected highly pathogenic avian influenza in any commercial US poultry. We will press trading partners in the coming days to bring their import restrictions in line with OIE [World Organizait9on for Animal Health] guidelines and the information we have provided them.”