Low-Pathogenic Influenza A Viruses in North American Diving Ducks Contribute to the Emergence of a Novel Highly Pathogenic Influenza A(H7N8) Virus

Authors

Yifei Xu, Mississippi State University
Andrew M. Ramey, U.S. Geological SurveyFollow
Andrew S. Bowman, Ohio State UniversityFollow
Thomas J. DeLiberto, USDA/APHIS/WS National Wildlife Research CenterFollow
Mary L. Killian, USDA
Scott Krauss, St. Jude Children's Research Hospital
Jacqueline M. Nolting, Ohio State UniversityFollow
Mia Kim Torchetti, U.S. Department of Agriculture National Veterinary Services LaboratoriesFollow
Andrew B. Reeves, Ohio State University
Richard J. Webby, St. Jude Children’s Research Hospital
David E. Stallknecht, University of GeorgiaFollow
Xiu-Feng Wan, Mississippi State UniversityFollow

Document Type

Article

Date of this Version

5-2017

Citation

Xu Y, Ramey AM, Bowman AS, DeLiberto TJ, Killian ML, Krauss S, Nolting JM, Torchetti MK, Reeves AB, Webby RJ, Stallknecht DE, Wan X-F. 2017. Lowpathogenic influenza A viruses in North American diving ducks contribute to the emergence of a novel highly pathogenic influenza A(H7N8) virus. J Virol 91:e02208-16. https://doi.org/10.1128/JVI.02208-16.

Comments

U.S. government work.

Abstract

Introductions of low-pathogenic avian influenza (LPAI) viruses of subtypes H5 and H7 into poultry from wild birds have the potential to mutate to highly pathogenic avian influenza (HPAI) viruses, but such viruses’ origins are often unclear. In January 2016, a novel H7N8 HPAI virus caused an outbreak in turkeys in Indiana, USA. To determine the virus’s origin, we sequenced the genomes of 441 wild-bird origin influenza A viruses (IAVs) from North America and subjected them to evolutionary analyses. The results showed that the H7N8 LPAI virus most likely circulated among diving ducks in the Mississippi flyway during autumn 2015 and was subsequently introduced to Indiana turkeys, in which it evolved high pathogenicity. Preceding the outbreak, an isolate with six gene segments (PB2, PB1, PA, HA, NA, and NS) sharing >99% sequence identity with those of H7N8 turkey isolates was recovered from a diving duck sampled in Kentucky, USA. H4N8 IAVs from other diving ducks possessed five H7N8-like gene segments (PB2, PB1, NA, MP, and NS; >98% sequence identity). Our findings suggest that viral gene constellations circulating among diving ducks can contribute to the emergence of IAVs that affect poultry. Therefore, diving ducks may serve an important and understudied role in the maintenance, diversification, and transmission of IAVs in the wild-bird reservoir.