title: Lack of evidence for human-to-human transmission of avian influenza A (H9N2) viruses in Hong Kong, China 1999.
abstract: In April 1999, isolation of avian influenza A (H9N2) viruses from humans was confirmed for the first time. H9N2 viruses were isolated from nasopharyngeal aspirate specimens collected from two children who were hospitalized with uncomplicated, febrile, upper respiratory tract illnesses in Hong Kong during March 1999. Novel influenza viruses have the potential to initiate global pandemics if they are sufficiently transmissible among humans. We conducted four retrospective cohort studies of persons exposed to these two H9N2 patients to assess whether human-to-human transmission of avian H9N2 viruses had occurred. No serologic evidence of H9N2 infection was found in family members or health-care workers who had close contact with the H9N2-infected children, suggesting that these H9N2 viruses were not easily transmitted from person to person.
authors.affiliation: Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. tmu0@cdc.gov
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Uyeki
authors.forename: Yu-Hoi
authors.initials: YH
authors.lastname: Chong
authors.forename: Jacqueline M
authors.initials: JM
authors.lastname: Katz
authors.forename: Wilina
authors.initials: W
authors.lastname: Lim
authors.forename: Yuk-Yin
authors.initials: YY
authors.lastname: Ho
authors.forename: Sophia S
authors.initials: SS
authors.lastname: Wang
authors.forename: Thomas H F
authors.initials: TH
authors.lastname: Tsang
authors.forename: Winnie Wan-Yee
authors.initials: WW
authors.lastname: Au
authors.forename: Shuk-Chi
authors.initials: SC
authors.lastname: Chan
authors.forename: Thomas
authors.initials: T
authors.lastname: Rowe
authors.forename: Jean
authors.initials: J
authors.lastname: Hu-Primmer
authors.forename: Jensa C
authors.initials: JC
authors.lastname: Bell
authors.forename: William W
authors.initials: WW
authors.lastname: Thompson
authors.forename: Carolyn Buxton
authors.initials: CB
authors.lastname: Bridges
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Cox
authors.forename: Kwok-Hang
authors.initials: KH
authors.lastname: Mak
authors.forename: Keiji
authors.initials: K
authors.lastname: Fukuda
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001717:Birds; D002675:Child, Preschool; D015331:Cohort Studies; D018562:Disease Transmission, Infectious / Q000706:statistics & numerical data*; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D007223:Infant; D017758:Infectious Disease Transmission, Patient-to-Professional / Q000706:statistics & numerical data*; D053127:Influenza A Virus, H9N2 Subtype; D009980:Influenza A virus / Q000276:immunology / Q000302:isolation & purification* / Q000472:pathogenicity*; D005585:Influenza in Birds / Q000276:immunology / Q000635:transmission*; D012189:Retrospective Studies
chemical_list: D000914:Antibodies, Viral