Avian Flu Detected in Pigs for the First Time in U.S.

Federal officials have announced the first H5N1 avian flu detection in pigs on a backyard farm in Oregon. CIDRAP has the news.

Potential spread of H5N1 to pigs was a concern “due to the impact on farming and food supply, but also because pigs are known to be a mixing vessel for zoonotic and human influenza viruses. However, it’s not yet clear if the pigs had systemic infection or if contamination on the farm led to positive nasal swab results.”

The pigs shared “water sources, housing, and equipment” with sick poultry. The pigs showed no signs of illness but were euthanized for “additional diagnostic analysis.” Test results were negative for two pigs and are pending for two others. Genetic sequencing is being performed at the USDA’s National Veterinary Services Laboratories, and officials say “there are no H5N1 changes to suggest the virus is more transmissible to humans.”

It is not yet known if the pig “was truly infected or if the nasal passages had been contaminated by environmental exposure, a situation strongly suspected when a Colorado poultry culler tested positive in 2022 during nasal swabbing that was done as part of illness monitoring.”