title: Surveillance for Eurasian-origin and intercontinental reassortant highly pathogenic influenza A viruses in Alaska, spring and summer 2015.
abstract: BACKGROUND
  Eurasian-origin and intercontinental reassortant highly pathogenic (HP) influenza A viruses (IAVs) were first detected in North America in wild, captive, and domestic birds during November-December 2014. Detections of HP viruses in wild birds in the contiguous United States and southern Canadian provinces continued into winter and spring of 2015 raising concerns that migratory birds could potentially disperse viruses to more northerly breeding areas where they could be maintained to eventually seed future poultry outbreaks.
  
  
  RESULTS
  We sampled 1,129 wild birds on the Yukon-Kuskokwim Delta, Alaska, one of the largest breeding areas for waterfowl in North America, during spring and summer of 2015 to test for Eurasian lineage and intercontinental reassortant HP H5 IAVs and potential progeny viruses. We did not detect HP IAVs in our sample collection from western Alaska; however, we isolated five low pathogenic (LP) viruses. Four isolates were of the H6N1 (n = 2), H6N2, and H9N2 combined subtypes whereas the fifth isolate was a mixed infection that included H3 and N7 gene segments. Genetic characterization of these five LP IAVs isolated from cackling (Branta hutchinsii; n = 2) and greater white-fronted geese (Anser albifrons; n = 3), revealed three viral gene segments sharing high nucleotide identity with HP H5 viruses recently detected in North America. Additionally, one of the five isolates was comprised of multiple Eurasian lineage gene segments.
  
  
  CONCLUSIONS
  Our results did not provide direct evidence for circulation of HP IAVs in the Yukon-Kuskokwim Delta region of Alaska during spring and summer of 2015. Prevalence and genetic characteristics of LP IAVs during the sampling period are concordant with previous findings of relatively low viral prevalence in geese during spring, non-detection of IAVs in geese during summer, and evidence for intercontinental exchange of viruses in western Alaska.
authors.affiliation: U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK, 99508, USA. aramey@usgs.gov.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Ramey
authors.affiliation: U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK, 99508, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Pearce
authors.affiliation: U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK, 99508, USA.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Reeves
authors.affiliation: Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, 589 D. W. Brooks Drive, University of Georgia, Athens, GA, 30602, USA.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Poulson
authors.affiliation: Yukon-Kuskokwim Health Corporation, 900 Chief Eddie Hoffman Highway, Bethel, AK, 99559, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Dobson
authors.affiliation: Yukon-Kuskokwim Health Corporation, 900 Chief Eddie Hoffman Highway, Bethel, AK, 99559, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Lefferts
authors.affiliation: U.S. Geological Survey, Western Ecological Research Center, San Francisco Bay Estuary, 505 Azuar Drive, Vallejo, CA, 94592, USA.|U.S. Fish and Wildlife Service, Yukon Delta National Wildlife Refuge, 807 Chief Eddie Hoffman Highway, Bethel, AK, 99559, USA.
authors.forename: Kyle
authors.initials: K
authors.lastname: Spragens
authors.affiliation: Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, 589 D. W. Brooks Drive, University of Georgia, Athens, GA, 30602, USA.
authors.forename: David E
authors.initials: DE
authors.lastname: Stallknecht
mesh_terms: D000413:Alaska / Q000453:epidemiology; D000818:Animals; D001717:Birds; D062665:Epidemiological Monitoring; D005838:Genotype; D009980:Influenza A virus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D005585:Influenza in Birds / Q000453:epidemiology* / Q000635:transmission / Q000821:virology*; D017720:Molecular Epidemiology; D016865:Reassortant Viruses / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D017422:Sequence Analysis, DNA
keywords: Alaska; H5N1; H5N2; H5N8; Highly pathogenic; Influenza; Migratory bird; Yukon-Kuskokwim Delta