A recent investigation by the CDC and Colorado health officials revealed a cluster of nine H5N1 avian flu cases among poultry cullers in Colorado, marking the first known human cluster linked to poultry exposure in the U.S. The outbreaks occurred during a culling operation following two H5N1 outbreaks at large layer farms, with 109 out of 663 workers reporting symptoms. All nine infected individuals exhibited mild symptoms, primarily conjunctivitis, and were treated with oseltamivir. Concurrently, the California Department of Food and Agriculture is investigating suspected H5N1 infections in three dairy herds, with no confirmed cases yet. The virus has been detected in cattle across 13 states, raising concerns about its potential to mutate and spread to humans. Health officials emphasize that pasteurization effectively inactivates the virus in dairy products, posing no safety risk to consumers.