State health department reports or CDC announcements

California Reports First Two Human H5N1 Cases Amid 55 Dairy Herd Outbreaks

Oct 3, 2024, 12:38 PM

An outbreak of H5N1 avian influenza has been detected in dairy cattle herds in California and Idaho, with California reporting 55 affected herds and Idaho reporting 34. The cumulative national total has reached 256 herds across 14 states. The California Department of Public Health, in collaboration with the CDC, confirmed two human cases of H5N1 in the state's Central Valley; both individuals are dairy workers who had contact with infected cattle and experienced mild symptoms, including conjunctivitis. There is no known link between the two cases. These infections mark the first reported human H5N1 cases in California and bring the total number of human cases in the U.S. to 15 this year. Officials emphasize that the risk to the public is low.