CDC A(H5N1) Bird Flu Response Update

CDC continues to respond to the public health challenge posed by a multistate outbreak of avian influenza A(H5N1) virus, or “A(H5N1) virus,” in dairy cows and other animals in the United States. CDC is working in collaboration with the U.S. Department of Agriculture (USDA), the Food and Drug Administration (FDA), state public health and animal health officials, and other partners using a One Health approach. On May 30, 2024, CDC reported that an additional human case of highly pathogenic avian influenza (HPAI) A(H5) virus infection was identified in Michigan. This is the third human case associated with an ongoing multistate outbreak of A(H5N1) in U.S. dairy cows.[1] As with the previous two cases (one in Texas, one in Michigan), the person is a dairy farm worker who had exposure to sick cows, making this another instance of likely cow-to-person spread. Based on the information available at this time, this case does not change CDC’s current A(H5N1) bird flu human health risk assessment for the U.S. general public because all three sporadic cases had direct contact with infected cows. On the animal health side, USDA is reporting that 68 dairy cow herds in nine U.S. states have confirmed cases of A(H5N1) virus infections in dairy cows.