CDFA Public Notice Regarding H5N9 Strain of Avian Influenza

Highly Pathogenic Avian Influenza (Bird Flu) H5N9 Strain Detected for the First Time in California, A Different Strain than H5N1A commercial duck flock in Merced County, confirmed to have H5N1 bird flu on December 14, 2024, received secondary testing and the final report on January 13, 2025 confirmed the presence of a different, additional strain of bird flu---H5N9. This was reported to the World Organization for Animal Health (WOAH) per protocol and published on January 24, 2025.