CDC has confirmed two human cases of H5 bird flu in California. Both of the cases occurred in people with “occupational exposure to infected dairy cows.”
This identification in people exposed to infected animals is “not unexpected and does not change CDC's risk assessment for the general public, which continues to be low. At this time, there is no known link or contact between the first and second confirmed cases in California, suggesting these are separate instances of animal-to-human spread of the virus.”
These cases are the first among humans in California, “where H5N1 outbreaks among dairy herds were first reported in August 2024. H5N1 bird flu was detected for the first time in cows this year in the United States.” Including this most recent case, “16 human cases of H5 have been reported in the United States during 2024, bringing the total to 17 cases since 2022. Cases during 2024 have been reported in Texas (1), Michigan (2), Colorado (10), Missouri (1) and California (2). Six of the 16 reported human cases have been linked to exposure to sick or infected dairy cows. Nine cases had exposure to infected poultry. The source of infection for the one case in Missouri has not been determined.”
HPN has reported on these H5N1 outbreaks over the past year.
