Epidemiological characteristics and influencing factors of influenza like illness cases in Wuxi city

Objective To analyze the epidemiological characteristics of influenza like illness(ILI) and the influencing factors in Wuxi city for the disease control and prevention.Methods The reported data of ILI outbreaks in 2009 were collected,and influenza and the other respiratory viruses were detected by mRT-PCR method,and positive cases were identified by RT-PCR method.Result Totally 33 outbreaks(1 006 cases and attack rate was 1.4%) in 2009 and all of them were in schools,mainly in September.The mean interval between outbreaks and reporting was 5 days.The epidemic duration was related to the school levels(township,county or city) and reporting in time.The incidence rates were related to the existed case numbers at reporting date and reporting in time.Totally 238 samples were collected and positive rate was 37.8%.The predominate virus trains were H1N1 and H3N2.Conclusion The main characteristics of influenza epidemics were sporadic cases and locally outbreaks in 2009 in Wuxi.The outbreaks reporting in time was very important for the disease control.