Abstract Highly pathogenic avian influenza virus of the H5N1 subtype has been infecting U.S dairy cattle and spreading among dairy farms since March 2024 . H5N1 surveillance systems for dairy farms are needed, but information on whether environmental sampling can inform these systems is lacking. To guide a surveillance framework , we determined the environmental locations on H5N1-affected dairies (n = 25) in four states (California, Colorado, Michigan, and Ohio) that harbored influenza A virus (IAV), and explored sample characteristics that may influence viral detection. A total of 623 samples from environments and sale barns were characterized for IAV and classified into six categories based on location. A total of 94 samples ( 15.1% ) had IAV detected , the majority in the following categories: milking equipment/personal protective equipment , parlor surfaces , and wastewater/lagoons/manure . These results suggest that dairy environments most likely to harbor IAV are those with...
Media Monitoring for Signals about Emerging Threats