H5N1 highly pathogenic avian influenza clade 188.8.131.52b in wild and domestic birds: Introductions into the United States and reassortments, December 2021–April 2022
Highly pathogenic avian influenza viruses (HPAIVs) of the A/goose/Guangdong/1/1996 lineage H5 clade 184.108.40.206b continue to have a devastating effect on domestic and wild birds. Full genome sequence analyses using 1369 H5N1 HPAIVs detected in the United States (U.S.) in wild birds, commercial poultry, and backyard flocks from December 2021 to April 2022, showed three phylogenetically distinct H5N1 virus introductions in the U.S. by wild birds. Unreassorted Eurasian genotypes A1 and A2 entered the Northeast Atlantic states, whereas a genetically distinct A3 genotype was detected in Alaska. The A1 genotype spread westward via wild bird migration and reassorted with North American wild bird avian influenza viruses. Reassortments of up to five internal genes generated a total of 21 distinct clusters; of these, six genotypes represented 92% of the HPAIVs examined. By phylodynamic analyses, most detections in domestic birds were shown to be point-source transmissions from wild birds, with limited farm-to-farm spread.
|H5N1 highly pathogenic avian influenza clade 220.127.116.11b in wild and domestic birds: Introductions into the United States and reassortments, December 2021–April 2022
|Sungsu Youk, Mia Kim Torchetti, Kristina Lantz, Julianna B. Lenoch, Mary Lea Killian, Christina Leyson, Sarah N. Bevins, Krista Dilione, Hon S. Ip, David E. Stallknecht, Rebecca L. Poulson, David L. Suarez, David E. Swayne, Mary J. Pantin-Jackwood
|USGS Publications Warehouse
|National Wildlife Health Center