Lack of evidence for human-to-human transmission of avian influenza A (H9N2) viruses in Hong Kong, China 1999.
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.
Uyeki
Timothy M
TM
Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. tmu0@cdc.gov
Chong
Yu-Hoi
YH
Katz
Jacqueline M
JM
Lim
Wilina
W
Ho
Yuk-Yin
YY
Wang
Sophia S
SS
Tsang
Thomas H F
TH
Au
Winnie Wan-Yee
WW
Chan
Shuk-Chi
SC
Rowe
Thomas
T
Hu-Primmer
Jean
J
Bell
Jensa C
JC
Thompson
William W
WW
Bridges
Carolyn Buxton
CB
Cox
Nancy J
NJ
Mak
Kwok-Hang
KH
Fukuda
Keiji
K
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
D000914:Antibodies, Viral