title: Evolution of highly pathogenic avian influenza (H5N1) virus populations in Vietnam between 2007 and 2010.
abstract: We report on the genetic analysis of 213 highly pathogenic avian influenza (HPAI) H5N1 viruses isolated from poultry in Vietnam between 2007 and 2010. Phylogenetic analyses of the viral genomes revealed 38 distinct viral genotypes, 29 were novel and 9 were reported in Vietnam or neighboring countries in recent years. Viruses from only six genotypes persisted beyond one season or year. Thus, most reassortant viruses were transient, suggesting that such genotypes lacked significant fitness advantages. Viruses with clade 2.3.2.1 HA were re-introduced into Vietnam in 2009 and their prevalence rose steeply towards the end of 2010. Clade 2.3.4-like viruses (genotype V) were predominant in northern Vietnam and caused the majority of zoonotic infections, whereas clade 1.1 (genotype Z) viruses were only detected in the Mekong delta region, in southern Vietnam. Antigenic analysis of representative viruses from the four clades indicated substantial drift.
authors: Graduate School, Hanoi University of Agriculture, Hanoi, Vietnam.
authors: Tung
authors: T
authors: Nguyen
authors: Pierre
authors: P
authors: Rivailler
authors: C Todd
authors: CT
authors: Davis
authors: Do Thi
authors: do T
authors: Hoa
authors: Amanda
authors: A
authors: Balish
authors: Nguyen Hoang
authors: NH
authors: Dang
authors: Joyce
authors: J
authors: Jones
authors: Dam Thi
authors: DT
authors: Vui
authors: Natosha
authors: N
authors: Simpson
authors: Ngo Thu
authors: NT
authors: Huong
authors: Bo
authors: B
authors: Shu
authors: Rosette
authors: R
authors: Loughlin
authors: Karen
authors: K
authors: Ferdinand
authors: Stephen E
authors: SE
authors: Lindstrom
authors: Ian A
authors: IA
authors: York
authors: Alexander
authors: A
authors: Klimov
authors: Ruben O
authors: RO
authors: Donis
mesh_terms: D000818:Animals; D002645:Chickens / Q000821:virology*; D004196:Disease Outbreaks; D004372:Ducks / Q000821:virology*; D019143:Evolution, Molecular; D005838:Genotype; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D005585:Influenza in Birds / Q000453:epidemiology* / Q000821:virology; D007251:Influenza, Human / Q000453:epidemiology; D010802:Phylogeny; D011201:Poultry Diseases / Q000453:epidemiology* / Q000821:virology; D015995:Prevalence; D016865:Reassortant Viruses / Q000235:genetics; D014744:Vietnam / Q000453:epidemiology; D015047:Zoonoses / Q000453:epidemiology / Q000821:virology
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus