title: [Virological and serological surveys for H9N2 subtype of influenza A virus in chickens and men in Shenzhen city].
abstract: OBJECTIVE
  To understand the distribution of influenza A H9N2 virus in chickens and men in Shenzhen area.
  
  
  METHODS
  Virus isolation was performed in embryonated hen s eggs with routine method. The antibody to H9N2 virus was detected with micro-hemagglutination inhibition (HI) test, then the results were checked by using the neutralization assay in MDCK cells.
  
  
  RESULTS
  Totally 27 strains of influenza A H9N2 virus were isolated from chickens in farm markets in Shenzhen, whereas no H9N2 virus was isolated from men. Approximately 26% of human sera with the HI titers > or =20 to H9N2 virus were detected. However only 7% of chicken sera with the HI titers > or =20 to H9N2 virus were detected. Meanwhile the HI titer and (MGT) of antibody to H9N2 virus in human sera increased with age. It was also found that there was a close relationship between HI antibody titer to H9N2 virus in human sera and occupation.
  
  
  CONCLUSIONS
  The distribution of influenza A H9N2 virus in chicken and men in Shenzhen was rather wide. The human H9N2 virus infection probably derived from chicken H9N2 virus.
authors.affiliation: Municipal Hygiene and Anti-epidemic Station of Shenzhen, Guangdong Province. Shenzhen 518020, China.
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Cheng
authors.forename: Jianjun
authors.initials: J
authors.lastname: Liu
authors.forename: Jianfan
authors.initials: J
authors.lastname: He
authors.forename: Fuxiang
authors.initials: F
authors.lastname: Shan
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002645:Chickens; D002681:China / Q000453:epidemiology; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D053127:Influenza A Virus, H9N2 Subtype; D009980:Influenza A virus / Q000145:classification / Q000276:immunology / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology*; D016036:Seroepidemiologic Studies
chemical_list: D000914:Antibodies, Viral