The report is the latest evidence that the outbreak in dairy herds is spreading undetected in cows, and the spillover into people at highest risk of exposure is going unnoticed.

More Americans could be unknowingly carrying bird flu, according to a new report from the Centers for Disease Control and Prevention. The report follows a series of random tests of 150 veterinarians,

Out of 150 participating veterinary practitioners across the country, three had antibodies indicating recent infection with Type A H5N1 bird flu, based on blood samples collected in September 2024, noted Samantha Olson, MPH, of the CDC's National Center for Immunization and Respiratory Diseases, and colleagues.