title: Mallards and highly pathogenic avian influenza ancestral viruses, northern Europe.
abstract: Outbreaks of highly pathogenic avian influenza (HPAI), which originate in poultry upon transmission of low pathogenic viruses from wild birds, have occurred relatively frequently in the last decade. During our ongoing surveillance studies in wild birds, we isolated several influenza A viruses of hemagglutinin subtype H5 and H7 that contain various neuraminidase subtypes. For each of the recorded H5 and H7 HPAI outbreaks in Europe since 1997, our collection contained closely related virus isolates recovered from wild birds, as determined by sequencing and phylogenetic analyses of the hemagglutinin gene and antigenic characterization of the hemagglutinin glycoprotein. The minor genetic and antigenic diversity between the viruses recovered from wild birds and those causing HPAI outbreaks indicates that influenza A virus surveillance studies in wild birds can help generate prototypic vaccine candidates and design and evaluate diagnostic tests, before outbreaks occur in animals and humans.
authors.affiliation: Department of Virology, Erasmus Medical Center, Rotterdam, the Netherlands.
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: Munster
authors.forename: Anders
authors.initials: A
authors.lastname: Wallensten
authors.forename: Chantal
authors.initials: C
authors.lastname: Baas
authors.forename: Guus F
authors.initials: GF
authors.lastname: Rimmelzwaan
authors.forename: Martin
authors.initials: M
authors.lastname: Schutten
authors.forename: Björn
authors.initials: B
authors.lastname: Olsen
authors.forename: Albert D M E
authors.initials: AD
authors.lastname: Osterhaus
authors.forename: Ron A M
authors.initials: RA
authors.lastname: Fouchier
mesh_terms: D000818:Animals; D000835:Animals, Wild / Q000821:virology*; D004196:Disease Outbreaks; D004372:Ducks / Q000821:virology*; D005060:Europe / Q000453:epidemiology; D006385:Hemagglutination Inhibition Tests; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000145:classification* / Q000235:genetics; D053125:Influenza A Virus, H5N2 Subtype / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D053126:Influenza A Virus, H7N7 Subtype / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D009980:Influenza A virus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D005585:Influenza in Birds / Q000453:epidemiology / Q000635:transmission / Q000821:virology*; D008297:Male; D008969:Molecular Sequence Data; D009439:Neuraminidase / Q000145:classification* / Q000235:genetics; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; C109963:hemagglutinin, avian influenza A virus; D009439:Neuraminidase