OLYMPIA — Bird flu could return next winter with new strains that are more prevalent in wild birds and more deadly for chickens, Washington State Veterinarian Joe Baker said July 6.
“We have to be ready for the worsening scenario,” he said.
The Washington State Department of Agriculture has been reviewing last year’s outbreak and planning to prevent and respond to a reoccurrence.
One lesson from last year: It could have been worse.
The virus in Washington was limited to a small percentage of wild ducks and raptors, four mixed-bird backyard flocks and a game bird farm of mostly pheasants. The outbreaks were spaced apart geographically and chronologically, keeping WSDA and the U.S. Department of Agriculture from being overwhelmed as they quarantined infected premises.
“Frankly, compared to what happened in the Mississippi Flyway, we got off pretty easy,” Baker said. “We can’t necessarily count on that good fortune the next time it hits.”
The first U.S. detection of highly pathogenic bird flu was in mid-December at a lake in northwest Washington. The disease appeared over the next two months throughout the West, including at two commercial poultry farms in California.
The Western outbreaks stopped in mid-February, but the virus resurfaced in early March in the Midwest, with much more disastrous consequences. More than 48 million birds in 15 states have been culled, according to the USDA. The last case was confirmed June 17 in Iowa.
The USDA investigated outbreaks at more than 80 commercial farms and concluded that while migratory birds introduced the virus, biosecurity lapses spread it. Equipment and humans traveled between infected barns in the country’s largest poultry producing states, the USDA reported.
Also, strong and sustained winds may have spread virus particles between barns, according to the agency.
Baker said he doesn’t see airborne spread as a threat in Washington because the state doesn’t have clusters of commercial poultry farms.
More concerning is that the virus may have adapted and become more lethal to chickens, he said.
For five weeks in the Midwest last spring, the virus struck only turkey farms, about 20. The virus finally infected a chicken farm in Wisconsin. After that, the disease broke out in chicken farms in several states.
In Washington last winter, the virus spread among flocks with a variety of birds. In Benton County, backyard chickens remained healthy though separated by only a mesh fence from an infected flock of chickens, turkeys and ducks.
A virus lethal to chickens may be spreading among waterfowl that spend the summer in Alaska and Canada and migrate to Washington for the winter, Baker said.“It could cause us more problems because there could be more spread (of the virus) neighbor to neighbor,” he said.
It’s unclear how common bird flu is among wild birds, which are not sickened by the virus. The USDA didn’t confirm a case of the virus in a wild bird outside the West until early March. Since then, cases in several states have been confirmed. In May, a dozen Canada geese tested positive in Michigan.
Baker said it’s possible the disease is spreading more widely now among migratory birds.
He said WSDA will try to impress upon farmworkers and backyard poultry enthusiasts the importance of preventive measures.
“Biosecurity is really something you have to live everyday. You can’t just talk about it. You can’t just draft plans,” Baker said.
WSDA has posted information about protecting flocks from bird flu at agr.wa.gov/FoodAnimal/AvianHealth/