Performance of automatic early warning system of communicable diseases in Huzhou,Zhejiang,2008-2013

Objective To evaluate the performance of the automatic early warning system of communicable diseases in Huzhou and provide evidence for the further improvement of the early warning system. Methods Descriptive epidemiological analysis was conducted to evaluate the effectiveness of communicable disease automatic early warning system in Huzhou from 2008 to 2013. Results A total of 4395 warning signals were generated during this period. The signal response rate was 100%, and the 24 h signal response rate was 89.08%. There was positive relationship between warning signal number and the case number reported by communicable diseases reporting network (P0.01), r=0.840. Moreover, 23 kinds of communicable diseases were involved, and the verification of the signals was mainly through comprehensive analysis, accounting for 74.47%. In addition, 54 warning signals were classified as suspected events, in which 11 were finally identified as outbreaks through field investigation. The sensitivity and the positive predicting value of the early warning system were 69.23% and 0.25% respectively. Conclusion The sensitivity of the automatic warning system of communicable diseases was high, but the positive predicting value was low in Huzhou. Further improvements are needed.