title: The genetic and antigenic diversity of avian influenza viruses isolated from domestic ducks, muscovy ducks, and chickens in northern and southern Vietnam, 2010-2012.
abstract: To estimate the prevalence of avian influenza virus infection in Vietnam, surveillance was conducted in domestic and wild birds from households, live-bird markets, slaughtering sites, and bird sanctuaries in Vietnam between October 2010 and October 2012. Of the 4,550 samples collected, 226 influenza A virus isolates were obtained from domestic ducks, muscovy ducks, and chickens. Of these, 25 and 22 H5N1 highly pathogenic avian influenza viruses (HPAIVs) were isolated from apparently healthy domestic ducks in live-bird markets and slaughtering sites in northern and southern Vietnam, respectively. The HA genes of H5 viruses isolated from birds in northern Vietnam phylogenetically belonged to the genetic clade 2.3.2.1 and those in southern Vietnam belonged to the genetic clade 1.1. In addition, 39 H3, 12 H4, 1 H5, 93 H6, 2 H7, 18 H9, 3 H10, and 11 H11 viruses were isolated. Phylogenetic and antigenic analyses of the H6 and H9 viruses revealed that they were closely related to the isolates obtained from domestic poultry in China. Phylogenetic analyses of internal gene segments of these isolates revealed that these viruses were circulating in both domestic and wild birds in Asia and reassortment events had occurred frequently. Therefore, it will be important to continue the surveillance and strict controls over the movement and trade of poultry and poultry products in order to eradicate H5N1 HPAIV from Asia.
authors.affiliation: Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, 060-0818, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Okamatsu
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nishi
authors.forename: Naoki
authors.initials: N
authors.lastname: Nomura
authors.forename: Naoki
authors.initials: N
authors.lastname: Yamamoto
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sakoda
authors.forename: Kenji
authors.initials: K
authors.lastname: Sakurai
authors.forename: Huy Duc
authors.initials: HD
authors.lastname: Chu
authors.forename: Long Pham
authors.initials: LP
authors.lastname: Thanh
authors.forename: Long
authors.initials: L
authors.lastname: Van Nguyen
authors.forename: Nam
authors.initials: N
authors.lastname: Van Hoang
authors.forename: Tien Ngoc
authors.initials: TN
authors.lastname: Tien
authors.forename: Reiko
authors.initials: R
authors.lastname: Yoshida
authors.forename: Ayato
authors.initials: A
authors.lastname: Takada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kida
mesh_terms: D000818:Animals; D000940:Antigenic Variation; D002645:Chickens; D016000:Cluster Analysis; D004372:Ducks; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics*; D009980:Influenza A virus / Q000235:genetics* / Q000276:immunology*; D005585:Influenza in Birds / Q000453:epidemiology / Q000821:virology*; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014744:Vietnam / Q000453:epidemiology
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; D012367:RNA, Viral