California Department of Public Health announcements or official reports

California Probes Second Child H5N1 Case as Outbreaks Hit 506 Herds

Dec 7, 2024, 03:24 PM

California is grappling with a significant outbreak of H5N1 avian influenza, with over 500 dairy cattle herds infected across the state, according to the U.S. Department of Agriculture (USDA). The virus has also impacted commercial poultry farms, with recent reports indicating outbreaks in five different counties. Amidst this, health officials are investigating a possible human case of H5N1 in a child from Marin County, marking the second such case in a child in California this year. The source of the child's exposure to the virus remains unknown, and confirmation is pending from state health authorities. If confirmed, this would be the 33rd human case in California and the sixth in the U.S. for December 2024. The total number of known mammal herds infected in the U.S. is 726, with 506 herds in California alone. There have been 75 human cases of H5N1 reported in the U.S. in 2024.