The Department of Agriculture confirmed highly pathogenic avian influenza H5 clade 2.3.4.4b by PCR testing in two Washington dairy herds. USDA says these are the state’s first confirmed livestock detections in the current outbreak.

The herds were tested after animals showed signs consistent with infection, despite earlier negative results through routine milk surveillance. Federal and state officials are conducting additional testing, sequencing, farm investigations and epidemiological data collection.

USDA says milk from affected animals is diverted or destroyed and does not enter the commercial supply. The Food and Drug Administration continues to consider pasteurization effective at inactivating the virus in milk.

The Centers for Disease Control and Prevention assesses risk to the general public as low, while people with occupational or recreational exposure to infected animals face higher risk. USDA is advising farms to strengthen biosecurity and promptly report illness.