[Application of EARS in early-warning of influenza pandemic in Beijing].
OBJECTIVE
To illustrate the efficiency of cumulative sum (CUSUM) in pre-warning of the influenza peak in Beijing.


METHODS
CUSUM was used to  analyze the data of influenza like illness (ILI), and the results of the influenza laboratory surveillance was regarded as the gold standard to judge the  approaching of the influenza peak.


RESULTS
The surveillance was launched in 421 hospitals in Beijing during the 2009 to 2010 influenza season, while the  influenza laboratory surveillance was launched by 7 collaborative laboratories. From Jun. 2009 to Apr. 2010, the average ILI percentage in the 421  hospitals was 2.56%. In the study, 19 262 pharyngeal swab samples were collected from the ILI cases in 11 hospitals and 5 045 of them were tested  positive for the influenza virus, with the novel swine-origin influenza A H1N1 virus dominating. After analyzing of the ILI surveillance data with CUSUM, it  was found that the ILI surveillance in Beijing could make a satisfactory early warning for the approaching of the influenza peak referring to the gold standard  based on the influenza laboratory results.


CONCLUSIONS
It could give the prediction and early warning for the influenza peak efficiently and precisely, by  using CUSUM to analyze the influenza surveillance data of Beijing.
Institute for Infectious Disease and Endemic Disease Control, Beijing Center for Disease Prevention and Control, Beijing, China.
Dai-tao
DT
Zhang
Peng
P
Yang
Yi
Y
Zhang
Li
L
Zhang
Xiao-min
XM
Peng
Wei-xian
WX
Shi
Gui-lan
GL
Lu
Hui-jie
HJ
Liang
Yi-meng
YM
Liu
Min
M
Liu
Quan-yi
QY
Wang
D000465:Algorithms; D055877:Biosurveillance / Q000379:methods*; D002681:China / Q000453:epidemiology; D003627:Data Interpretation, Statistical; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology*