The current strain of highly pathogenic avian influenza first hit the United States in January 2022. By April that year, it had been confirmed in both domestic and wild birds in Utah.
“When we first got it, we think it came over the polar ice caps into the U.S. After we had it in North America, it went south, it hit South America,” said Amanda Price, state veterinarian with the Utah Department of Agriculture and Food. She said this strain has continued to circulate since 2022, mostly spread by migratory birds.
“So, in the fall, it'll hit the northern states first, and then kind of track southward as it goes,” Price said.
In addition to wild birds, the virus can infect domestic flocks and dairy cattle. While Utah’s poultry and cattle have been impacted in the past, there are no current infections.
“We do have some concerning things going on in the states surrounding us. So, Arizona has had three egg layers hit since May 19. … And then Idaho has the dairy strain. They've had 17 new dairies in Idaho in the last 30 days that have come down with it,” Price said.
Utah monitors avian flu in dairy cattle by conducting monthly bulk tank testing of the milk. While cattle are relatively unaffected by the virus, Price said, they can spread it back to birds, where it is often fatal.
“So, last I heard, the dairy strain took out about 70% of California's egg layers. … I mean, the virus will pretty much wipe out the birds on its own, so we do cull poultry," Price said. "On the dairy side, it's just a matter of quarantining the facility; we don’t cull any of the dairy cattle.”
Price said she is working with other state vets and Utah officials to try to mitigate the spread of the disease.
“I'm hopeful, at some point, this is going to stop, and we won't have to continue to have these conversations," she said. But, you know, we're three years into it at this point, and we're still getting hit.”
