The U.S. Centers for Disease Control and Prevention (CDC) has confirmed highly pathogenic avian influenza (HPAI) in a person linked to a previously reported outbreak affecting birds at a commercial poultry operation in Clackamas County.
Health officials are not providing additional details about the individual or naming the operation, and will not provide specific location information to protect privacy. There is no evidence of person-to-person transmission and the risk to the public is low.
“Clackamas County Public Health Division has been closely monitoring people exposed to the animal outbreak, which is how this case was identified. The individual experienced only mild illness and has fully recovered,” said Clackamas County Public Health Officer Dr. Sarah Present. The person received treatment with the antiviral medication oseltamivir, and household contacts were prescribed oseltamivir prophylaxis.
“We continue to remind the public that people at increased risk of infection are those who have had close or prolonged, unprotected exposures to infected birds or other animals, or to environments contaminated by infected birds or other animals,” said Dr. Dean Sidelinger, health officer and state epidemiologist at Oregon Health Authority (OHA).
OHA epidemiologists are working closely with their counterparts at local public health authorities, Oregon Department of Agriculture (ODA) and CDC to monitor individuals exposed to animals infected with H5N1 and respond promptly if new symptoms consistent with avian influenza develop, Sidelinger said.
When an outbreak in animals occurs, ODA provides personal protective equipment and training to affected farmworkers, and public health authorities provides symptom education and monitoring.
“This has proven an extremely effective approach to avian influenza outbreaks,” Sidelinger said. “While we cannot prevent every case, we know that we are preventing many.”
To reduce the risk of HPAI, people should avoid contact with sick or dead birds or animals, or their droppings or litter, and should not drink or eat unpasteurized or raw dairy products such as milk or cheese.
HPAI cases in poultry, swine
Oregon’s first instance of HPAI in a commercial poultry flock in 2024 was confirmed in a commercial layer flock in Clackamas County, Oregon, on October 24 and involved 146,000 birds. On October 29, the U.S. Department of Agriculture National Veterinary Services Laboratories also confirmed one pig on a farm in Crook County, Oregon, to be infected with H5N1, marking the first detection of H5N1 in swine in the United States.
