title: Prevalence and subtypes of influenza A viruses in wild waterfowl in Norway 2006-2007.
abstract: The prevalence of influenza A virus infection, and the distribution of different subtypes of the virus, were studied in 1529 ducks and 1213 gulls shot during ordinary hunting from August to December in two consecutive years, 2006 and 2007, in Norway. The study was based on molecular screening of cloacal and tracheal swabs, using a pan-influenza A RT-PCR. Samples found to be positive for influenza A virus were screened for the H5 subtype, using a H5 specific RT-PCR, and, if negative, further subtyped by a RT-PCR for the 3'-part of the hemagglutinin (HA) gene, encompassing almost the entire HA2, and the full-length of the neuraminidase (NA) gene, followed by sequencing and characterization. The highest prevalence (12.8%) of infection was found in dabbling ducks (Eurasian Wigeon, Common Teal and Mallard). Diving ducks (Common Goldeneye, Common Merganser, Red-breasted Merganser, Common Scoter, Common Eider and Tufted Duck) showed a lower prevalence (4.1%). In gulls (Common Gull, Herring Gull, Black-headed Gull, Lesser Black-headed Gull, Great Black-backed Gull and Kittiwake) the prevalence of influenza A virus was 6.1%. The infection prevalence peaked during October for ducks, and October/November for gulls. From the 16 hemagglutinin subtypes known to infect wild birds, 13 were detected in this study. Low pathogenic H5 was found in 17 dabbling ducks and one gull.
authors.affiliation: Department of Animal Health, National Veterinary Institute, P,O Box 750 Sentrum, N-0106 Oslo, Norway. Anna.Germundsson@vetinst.no
authors.forename: Anna
authors.initials: A
authors.lastname: Germundsson
authors.forename: Knut I
authors.initials: KI
authors.lastname: Madslien
authors.forename: Monika Jankowska
authors.initials: MJ
authors.lastname: Hjortaas
authors.forename: Kjell
authors.initials: K
authors.lastname: Handeland
authors.forename: Christine Monceyron
authors.initials: CM
authors.lastname: Jonassen
mesh_terms: D000818:Animals; D000835:Animals, Wild; D001483:Base Sequence; D001715:Bird Diseases / Q000453:epidemiology / Q000821:virology*; D046091:Charadriiformes; D004372:Ducks; D006388:Hemagglutinins / Q000737:chemistry / Q000235:genetics; D009980:Influenza A virus / Q000235:genetics / Q000302:isolation & purification*; D005585:Influenza in Birds / Q000453:epidemiology / Q000821:virology*; D008969:Molecular Sequence Data; D009439:Neuraminidase / Q000737:chemistry / Q000235:genetics; D009664:Norway / Q000453:epidemiology; D015995:Prevalence; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012621:Seasons; D017422:Sequence Analysis, DNA
chemical_list: D006388:Hemagglutinins; D012367:RNA, Viral; D009439:Neuraminidase