[The virus isolation analysis of the H5N1 subtype human avain influenza cases in mainland China from 2005 to 2009].
OBJECTIVE
To analyse the correlation between the virus isolation and the specimen collection of the H5N1 human high pathogenic avain influenza cases in Mainland China.


METHODS
The specimens were collected in Mainland China from 2005.10 to 2009.3 and the H5N1 viruses were isolated by passage in embryonated chicken eggs.


RESULTS
Most specimens were obtained within 14 days after disease onset. For the specimens collected within 7 days, the isolation rate was relatively high and the difference of the positive rate between different years was lower than those specimens collected after 7 days. Most of the samples in our study were collected from the upper or lower respiratory tract with few from blood, feces, et al. The isolation rate of lower respiratory specimens was higher and the difference of the positive rate between different years was relatively lower than those from upper respiratory specimens.


CONCLUSIONS
We suggest that the samples should be collected from lower respiratory tract during the acute phase to get the higher isolation rate.
Zou
Shu-mei
SM
State Key Laboratory for Infectious Disease Prevention and Control, National Institute of Viral Disease Prevention and Control, China Center for Disease Prevention and Control, Beijing.
Zhang
Ye
Y
Li
Zi
Z
Dong
Jie
J
Zhao
Xin-sheng
XS
Dong
Li-bo
LB
Wen
Le-ying
LY
Xu
Cui-ling
CL
Wang
Min
M
Guo
Jun-feng
JF
Wei
He-jiang
HJ
Gao
Rong-bao
RB
Wang
Xiu-ping
XP
Shu
Yue-long
YL
D000818:Animals; D002642:Chick Embryo; D002681:China / Q000453:epidemiology; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology*; D012137:Respiratory System / Q000821:virology