title: Avian influenza in shorebirds: experimental infection of ruddy turnstones (Arenaria interpres) with avian influenza virus.
abstract: BACKGROUND
  Low pathogenic avian influenza viruses (LPAIV) have been reported in shorebirds, especially at Delaware Bay, USA, during spring migration. However, data on patterns of virus excretion, minimal infectious doses, and clinical outcome are lacking. The ruddy turnstone (Arenaria interpres) is the shorebird species with the highest prevalence of influenza virus at Delaware Bay.
  
  
  OBJECTIVE
  The primary objective of this study was to experimentally assess the patterns of influenza virus excretion, minimal infectious doses, and clinical outcome in ruddy turnstones.
  
  
  METHODS
  We experimentally challenged ruddy turnstones using a common LPAIV shorebird isolate, an LPAIV waterfowl isolate, or a highly pathogenic H5N1 avian influenza virus. Cloacal and oral swabs and sera were analyzed from each bird.
  
  
  RESULTS
  Most ruddy turnstones had pre-existing antibodies to avian influenza virus, and many were infected at the time of capture. The infectious doses for each challenge virus were similar (10(3·6) -10(4·16) EID(50)), regardless of exposure history. All infected birds excreted similar amounts of virus and showed no clinical signs of disease or mortality. Influenza A-specific antibodies remained detectable for at least 2 months after inoculation.
  
  
  CONCLUSIONS
  These results provide a reference for interpretation of surveillance data, modeling, and predicting the risks of avian influenza transmission and movement in these important hosts.
authors.affiliation: United States Geological Survey, National Wildlife Health Center, Madison, WI, USA.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Hall
authors.forename: Scott
authors.initials: S
authors.lastname: Krauss
authors.forename: J Christian
authors.initials: JC
authors.lastname: Franson
authors.forename: Joshua L
authors.initials: JL
authors.lastname: TeSlaa
authors.forename: Sean W
authors.initials: SW
authors.lastname: Nashold
authors.forename: David E
authors.initials: DE
authors.lastname: Stallknecht
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Webby
authors.forename: Robert G
authors.initials: RG
authors.lastname: Webster
mesh_terms: D000818:Animals; D000835:Animals, Wild / Q000821:virology; D000914:Antibodies, Viral / Q000097:blood; D001717:Birds / Q000821:virology; D046091:Charadriiformes / Q000821:virology*; D002988:Cloaca / Q000821:virology; D003691:Delaware; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology / Q000472:pathogenicity*; D053125:Influenza A Virus, H5N2 Subtype / Q000276:immunology / Q000472:pathogenicity*; D057920:Influenza A Virus, H7N3 Subtype / Q000276:immunology / Q000472:pathogenicity*; D005585:Influenza in Birds / Q000276:immunology / Q000503:physiopathology* / Q000635:transmission / Q000821:virology; D009055:Mouth / Q000821:virology; D017201:Virus Shedding
chemical_list: D000914:Antibodies, Viral