H5N1 bird flu was circulating in dairy cows for four months before it was detected, USDA scientists say

Bird flu may have been circulating in dairy cows for several months before it was identified as the highly pathogenic H5N1 virus. Genomic data analysis by scientists suggests that infected cattle have no apparent connections, indicating that there may be affected herds yet to be identified. Experts warn that the virus had a head start in the US dairy industry before being detected by scientists and regulators. The presence of H5N1 has since been confirmed in multiple herds across nine states. Existing tests indicate the presence of the virus in retail milk samples, but it is not active and poses no risk if consumed. Experts emphasize the need for routine and proactive testing of animals using modern techniques to prevent outbreaks.