evidence: September 27, 2024 – CDC continues to respond to the public health challenge posed by a multistate outbreak of avian influenza A(H5N1) virus, or "H5N1 bird flu," in dairy cows, poultry 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), Administration for Strategic Preparedness and Response (ASPR), state public health and animal health officials, and other partners using a One Health approach. [...] - Cumulatively, there have been 14 human cases of H5 bird flu reported in the United States. On July 14, 2024, CDC confirmed four human cases of H5 bird flu in Colorado, and additional (fifth and sixth) cases in Colorado were confirmed at CDC and were reported on July 19, 2024. Three additional cases in Colorado from a different farm were confirmed by CDC on July 25, 2024. Nine of these 14 cumulative human cases of H5 bird flu in the United States have been confirmed as avian influenza A(H5N1). The first human case of H5N1 bird flu in the United States was reported on April 28, 2022, in a person in Colorado who had direct exposure to poultry and who was involved in depopulating poultry with presumptive H5N1 bird flu. The 2022 human case was not related to dairy cows. The person only reported fatigue without any other symptoms and recovered.