Highly pathogenic avian influenza (HPAI) has been confirmed in a commercial laying hen flock in Clackamas County, Oregon, according to state and federal animal health agencies.

The Oregon Department of Agriculture (ODA) said samples from the flock were first tested at the Oregon Veterinary Diagnostic Laboratory at Oregon State University, which confirmed HPAI on Nov. 2. The U.S. Department of Agriculture (USDA) confirmed those results Nov. 4.

The USDA’s Animal and Plant Health Inspection Service(APHIS) reported that the flock included 94,200 laying hens.

In a press release, ODA said the state veterinarian has placed the farm under quarantine.

It is the first time in more than two years that HPAI has been confirmed in an Oregon commercial poultry operation. According to APHIS, the previous commercial case was confirmed Oct. 23, 2024, in a flock of 150,000 birds, also in Clackamas County. A human with connections to that flock also tested positive for the virus.

Since then, the virus has been confirmed in Oregon backyard poultry flocks, but under World Organisation for Animal Health (WOAH) rules, such infections should not affect international trade.

More information on Canadian HPAI cases

WOAH this week issued a report with additional details on two commercial poultry flock infections confirmed in September in the Canadian province of Manitoba.

The Canadian Food Inspection Agency (CFIA) previously reported that HPAI was confirmed in a commercial poultry operation in the Rural Municipality of Cartier on Sept. 21 and in another commercial poultry farm in the Rural Municipality of Woodlands on Sept. 22. However, CFIA did not disclose the types of poultry or the number of birds involved.

According to the WOAH report, the Cartier case involved a mixed flock of 28,521 broilers and laying hens. The Woodlands case also involved a mixed flock, with 45,845 commercial broilers, laying hens, turkeys, geese and ducks.

Source here