The Arizona Department of Agriculture (AZDA), in collaboration with the United States Department of Agriculture (USDA), confirmed the presence of the H5N1 avian influenza virus in milk from a dairy herd in Maricopa County.
This marks Arizona’s first detection of H5N1 in dairy cattle.
The affected facility has been placed under quarantine as a precautionary measure. Notably, the cattle have not exhibited any signs of illness associated with the virus.
The detected H5N1 strain is identified as the D1.1 genotype, which, according to AZDA, lacks features that would increase its likelihood of infecting humans.
This detection resulted from AZDA’s implementation of the National Milk Testing Strategy in January, focusing on farm-level bulk tank testing.
To date, all other dairy facilities in Arizona have tested negative for H5N1.
Health officials emphasize that pasteurized milk and dairy products remain safe for consumption, as the pasteurization process effectively inactivates the virus.
The AZDA is collaborating closely with the Arizona Department of Health Services and the Maricopa County Department of Public Health to provide safety guidance and monitor the situation.
While the risk to the general public is considered low, individuals in close contact with dairy cattle are advised to follow recommended safety protocols to prevent potential transmission.
This incident is part of a broader pattern of H5N1 detections in various species across the United States.
The virus, which primarily affects birds, has occasionally spilled over into mammals, including dairy cattle.
Health authorities continue to monitor the situation closely to mitigate further spread and ensure public safety.
