Performance of communicable disease automatic early warning information system in Ningbo city in Zhejiang province,2008-2010

Objective To understand the performance of communicable disease automatic early warning information system in Ningbo during 2008-2010 and provide scientific evidence for the improvement of the early warning system.Methods Descriptive epidemiological analysis was conducted on the data obtained from the communicable disease early warning information system.Results Totally 14 581 warnings about disease outbreaks were released by the warning system from 21 April 2008 to 31 December 2010,and 17 of them were confirmed by field investigation.In these outbreaks,24 communicable diseases were identified,and the first 5 diseases were other infectious diarrhea,mumps,measles,rubella and acute hemorrhagic conjunctivitis.The warnings were mainly released during May-July and in September.The median response time was 1 hour,and the field investigations were conducted averagely 80 hours before online reporting.The positive predictive value of the warning system was only 0.12%,the sensitivity was 53.13%.Conclusion The performance of communicable disease automatic early-warning system was good in Ningbo,which played an important role in the early detection of priority disease as cholera.However,the warning parameters and mechanism should be further adjusted and improved,and gold standard should be set for the scientific evaluation of communicable disease early warning.