California Records the Most Bird Flu Cases

Cumulative data on cases of the currently circulating H5N1 flu shows that outbreaks have been ongoing in the United States since at least 2022 (when data started being collected on the disease in wild birds, poultry and humans; cumulative data started being collected among cattle only in March, 2024).

According to the Centers for Disease Control and Prevention (CDC), as of December 13, 2024, there have been 60 confirmed cases of the disease in humans, 37 of which were transmitted from dairy cows. Since 2022, 21 cases have been transmitted from poultry (11 cases in Washington, 9 in Colorado and one in Oregon) and two cases are recorded with an unknown source (one in California, one in Missouri).

The current public health risk is considered low, with no cases of person-to-person transmission recorded. The CDC is watching the situation carefully and working with states to monitor people with animal exposures.