U.S.: first outbreak of H7N9 bird flu on farm since 2017
The United States has reported its first outbreak of H7N9 avian influenza on a poultry farm since 2017, as stated by the World Organisation for Animal Health (WOAH).
The highly pathogenic avian influenza (HPAI) H7N9, which originates from the North American wild bird lineage, was detected in a commercial broiler breeder flock in Mississippi in Noxubee County. Depopulation of 47,654 birds at the facility was completed on March 13. This H7N9 virus is a fully North American (AM) virus of wild bird-origin and is unrelated to the Eurasian H5N1 clade 2.3.4.4b virus currently circulating in the United States. Some AM H7 LPAI viruses detected as part of APHIS’ wild bird surveillance are closely related to this HPAI virus, indicating a recent spillover of wild bird-origin LPAI virus.
