[Investigation on the source of the first human of avian influenza A (H5N1) case in Beijing].
OBJECTIVE
To investigate the source of the first human case of avian influenza A (H5N1) infection in Beijing.


METHODS
Interviewing the relatives of the case and other key persons, collecting and detecting samples of related biological, epidemiological and environmental data of the case were conducted. Later, the infection source was thoroughly investigated.


RESULTS
The case ever contacted a slaughtered duck 5 days prior to the onset of illness, and the duck was bought from a stall of a wet market in Yanjiao area of Hebei province. Ten environmental samples were collected in this stall and the neighboring stall of the market. Another 6 samples were tested positive for H5N1 virus by PCR method, with 5 virus strains isolated. The whole-genome sequencing indicated that the amino acid homology between the H5N1 virus strains from the environment and the virus isolated from the case reached 99.8% - 100%.


CONCLUSIONS
From both epidemiological and virological evidence, it was proved that the first human case of avian influenza A (H5N1) infection in Beijing was infected by a duck that carrying H5N1 virus the case contacted 5 days proceeding the onset of illness.
Yang
Peng
P
Institute of Infectious and Endemic Diseases Control, Beijing Center for Disease Control and Prevention, Beijing 100013, China.
Shi
Jian
J
Ma
Jian-xin
JX
Liu
Xiu-jun
XJ
Qi
Shun-xiang
SX
Huang
Fang
F
Shi
Wei-xian
WX
Peng
Xiao-min
XM
Lv
Yan-ning
YN
Liang
Hui-jie
HJ
Li
Xin-yu
XY
Dou
Xiang-feng
XF
Wang
Xiao-li
XL
Zhang
Yi
Y
Pang
Xing-huo
XH
He
Xiong
X
Wang
Quan-yi
QY
D000328:Adult; D000818:Animals; D002681:China / Q000453:epidemiology; D004372:Ducks / Q000821:virology*; D005260:Female; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology*