Widespread detection of highly pathogenic H5 influenza viruses in wild birds from the Pacific Flyway of the United States

Authors

S. N. Bevins, US Department of Agriculture–National Wildlife Research CenterFollow
R. J. Dusek, US Geological Survey– National Wildlife Health Center
C. L. White, US Geological Survey– National Wildlife Health Center
T. Gidlewski, US Department of Agriculture–National Wildlife Research CenterFollow
B. Bodenstein, US Geological Survey– National Wildlife Health Center
K. G, Mansfield, Washington Department of Fish and Wildlife
P. DeBruyn, Washington Department of Fish and Wildlife
D. Kraege, Washington Department of Fish and Wildlife
E. Rowan, Washington Department of Fish and Wildlife
C. Gillin, Oregon Department of Fish and Wildlife
B. Thomas, USDA Wildlife Services
S. Chandler, USDA Wildlife Services
J. A. Baroch, USDA/APHIS/WS National Wildlife Research CenterFollow
B. S. Schmit, USDA/APHIS/WS National Wildlife Research CenterFollow
M. J. Grady, US Department of Agriculture–National Wildlife Research Center
R. S. Miller, USDA Veterinary Services
M. L. Drew, Idaho Department of Fish and Game
S. Stopak, USDA Wildlife Services
B. Zscheile, USDA Wildlife Services
J. Bennett, USDA Wildlife Services
J. Sengl, USDA Wildlife Services
Caroline Brady, California Waterfowl Association
H. S. Ip, US Geological Survey– National Wildlife Health Center
E. Spackman, USDA ARS Southeast Poultry Research LaboratoryFollow
M. L. Killian, US Department of Agriculture
M. K. Torchetti, US Department of AgricultureFollow
J. M. Sleeman, US Geological Survey– National Wildlife Health Center
T. J. Deliberto, USDA/APHIS/WS National Wildlife Research CenterFollow

Date of this Version

2016

Citation

Scientific Reports 6:28980

Comments

U.S. Government Work

Abstract

A novel highly pathogenic avian influenza virus belonging to the H5 clade 2.3.4.4 variant viruses was detected in North America in late 2014. Motivated by the identification of these viruses in domestic poultry in Canada, an intensive study was initiated to conduct highly pathogenic avian influenza surveillance in wild birds in the Pacific Flyway of the United States. A total of 4,729 hunter-harvested wild birds were sampled and highly pathogenic avian influenza virus was detected in 1.3% (n = 63). Three H5 clade 2.3.4.4 subtypes were isolated from wild birds, H5N2, H5N8, and H5N1, representing the wholly Eurasian lineage H5N8 and two novel reassortant viruses. Testing of 150 additional wild birds during avian morbidity and mortality investigations in Washington yielded 10 (6.7%) additional highly pathogenic avian influenza isolates (H5N8 = 3 and H5N2 = 7). The geographically widespread detection of these viruses in apparently healthy wild waterfowl suggest that the H5 clade 2.3.4.4 variant viruses may behave similarly in this taxonomic group whereby many waterfowl species are susceptible to infection but do not demonstrate obvious clinical disease. Despite these findings in wild waterfowl, mortality has been documented for some wild bird species and losses in US domestic poultry during the first half of 2015 were unprecedented.