title: Pathogenicity of H5N1 influenza A viruses isolated in Vietnam between late 2003 and 2005.
abstract: Since late 2003, highly pathogenic H5N1 influenza A viruses have spread among poultry and wild aquatic birds in Asian countries. Transmission of these viruses to humans can be lethal. Most human cases of infection with H5N1 viruses have occurred in Vietnam. Therefore, to understand the pathogenicity in mammals of these H5N1 viruses, we took viruses isolated from poultry (5 strains) and humans (2 strains) in Vietnam and tested their virulence in mice. The results showed that the H5N1 viruses from humans were pathogenic in mice and that one avian isolate was also pathogenic. These findings suggested that the H5N1 viruses circulating in poultry adapted during replication in humans or that strains pathogenic in mice were transmitted directly to humans.
authors.affiliation: International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, Tokyo, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Muramoto
authors.forename: Thi Quynh Mai
authors.initials: TQ
authors.lastname: Le
authors.forename: Lien Song
authors.initials: LS
authors.lastname: Phuong
authors.forename: Tung
authors.initials: T
authors.lastname: Nguyen
authors.forename: Thu Ha
authors.initials: TH
authors.lastname: Nguyen
authors.forename: Yuko
authors.initials: Y
authors.lastname: Sakai-Tagawa
authors.forename: Taisuke
authors.initials: T
authors.lastname: Horimoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kida
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kawaoka
mesh_terms: D000818:Animals; D001717:Birds; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000302:isolation & purification* / Q000472:pathogenicity*; D005585:Influenza in Birds / Q000453:epidemiology / Q000821:virology*; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology*; D051379:Mice; D008807:Mice, Inbred BALB C; D014744:Vietnam / Q000453:epidemiology; D014774:Virulence