Sequencing-Based Detection of Avian Influenza A(H5N1) Virus in Wastewater in Ten Cities

Highly pathogenic avian influenza viruses are virulent members of the H5 and H7 subtypes of influenza A virus, cause systemic disease in avian species, and incur substantial costs to agricultural production because of the need for mass culling of infected animals.¹ Since 1955, most avian influenza outbreaks have been caused by three lineages; one of them (a lineage that infected poultry) gave rise to the 2.3.4.4b clade, which has recently become widespread. On March 25, 2024, H5N1 2.3.4.4b was detected in dairy cattle herds in Texas concomitantly with herds in Michigan...