Intercontinental Movement of Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4 Virus to the United States, 2021

Abstract

We detected Eurasian-origin highly pathogenic avian influenza A(H5N1) virus belonging to the Gs/GD lineage, clade 2.3.4.4b, in wild waterfowl in 2 Atlantic coastal states in the United States. Bird banding data showed widespread movement of waterfowl within the Atlantic Flyway and between neighboring flyways and northern breeding grounds.