The United States has reported its first outbreak of H5N9 avian influenza in poultry, discovered at a duck farm in California. Authorities also identified the more prevalent H5N1 strain at the same location in Merced County. Nearly 119,000 birds at the farm were culled by early December to prevent further spread.
Highly pathogenic avian influenza (HPAI), often referred to as bird flu, has been spreading globally in recent years. This has led to the mass culling of poultry worldwide and has affected various mammal species, including dairy cows in the U.S. It has also resulted in at least one human fatality in Louisiana.
While H5N1 has been the dominant strain causing significant outbreaks, H5N9 remains less common. This marks the first recorded instance of H5N9 in U.S. poultry. Federal and state agricultural officials are conducting detailed investigations and bolstering surveillance efforts in response to these events.
