Published 11:15 am Friday, March 18, 2022
Experts are urging Northwest farmers with poultry and other birds to boost their biosecurity measures as highly pathogenic avian influenza — known by the initials HPAI — spreads along migratory bird pathways in the Midwest and along the East Coast.
Detection in waterfowl is usually the first sign of an outbreak, said Dr. Amber Itle, Washington state veterinarian. So far, HPAI has been detected in 21 states, but not in the Pacific Flyway.
There are four migratory bird flyways in North America: the Pacific, Central, Mississippi and Atlantic.
The current avian influenza outbreak has resulted in the culling of 7 million birds in 13 states, mostly within the Atlantic and Central flyways, Itle said.
“Typically, birds fly north to south, they don’t usually fly east to west,” Itle said, adding that there is still some risk of crossover.
Itle said federal and state officials are monitoring the situation.
West Coast officials will become more concerned if HPAI is detected in wild waterfowl in the Pacific flyway, she said.
On March 2, the World Organization for Animal Health confirmed a bald eagle found dead in British Columbia, Canada, tested positive for HPAI Eurasian strain H5N1.
Itle said the HPAI was found through genomic sequencing to be a novel strain, likely fed to the eagle through an infected duck at a rehabilitation center.
“It’s unrelated to the current outbreak and it’s not an indicator of early disease here in the Pacific flyway,” she said.
So far, HPAI has been detected in 23 commercial poultry operations and 16 backyard flocks in the U.S. The farthest west the flu has appeared is Iowa.
Flocks where the disease has been detected range in size from 8 to nearly 3 million birds.
“You can imagine how the response can look really different,” depending on the flock size, Itle said.
During an outbreak, turkeys, chickens, quail, game birds, waterfowl and red-meat birds like ostriches and emus are tested, said Steph Herbstritt, livestock and natural resources educator for Cornell University Cooperative Extension in New York.
Waterfowl droppings are the most infectious, and the birds are at the highest risk in areas where they congregate.
Itle recommends housing domestic ducks separate from other birds and not using water from a natural source because of the higher potential for infection.
“You want to think about how that fecal material can be moved physically,” she said. “Not just from the waterfowl, but we can move it on our shoes, trucks, clothing, equipment, and then also rodents. Rodents can move it on their feet between chicken coops.”
In 2015, 50 million chickens or turkeys were culled at 200 farms in 15 states during an avian flu outbreak.
Through genomic sequencing, officials found two point sources of infection, Itle said.
“That means only two birds, like wild waterfowl,” she said.
Itle said the problem was breaches in biosecurity, with farmers sharing trucks and equipment and going to the same locations.
This year, genomic sequencing shows almost all detections are likely separate introductions by waterfowl, she said.
“We’re doing a better job of not transmitting it from farm to farm,” she said, but the infection is still getting from waterfowl to the flocks.
The Oregon Department of Agriculture asks bird owners to report unusual increases in illness or death rates in their flocks. If you find a sick or dead bird, don’t touch it, report it.
Email npip@oda.oregon.gov or call 1-800-347-7028
If you find a dead or sick wild bird, report to the Oregon Department of Fish and Wildlife by calling 1-866-968-2600.
WSDA Sick Bird Hotline at 1-800-606-3056
https://agri.idaho.gov/main/animals/avian-species/avian-disease/avian-influenza/
