Analysis on influenza surveillance data in Jiangsu province from 2004 to 2007

Objective To understand the epidemiologic characters of influenza in Jiangsu prov ince and to evaluate the in fluenza surveillance measures available so as to provide scientific evidence for making preventive and control strategies of in fluenza.Methods To analyze data collected from epidemiological,pathog enic and outbr eak surveillance from Januar y,2004 to May,2007.Results According to the surv eillance of influenza-like illness(ILI)in sentinel hospitals,it showed two peaks distr ibuted in winter-spring and summer in Jiangsu province.The majority of ILI distributed in people aged below 5.The construction of subtype strains usually changed around September.Most of outbreaks occurred in primary and middle schools,and frequently in winter and spring.Conclusion More attention should be paid to the variation of virus strains and school outbreak surveillance should be enhanced.Given that sentinel hospital-based surveillance system has its weaknesses and the ILI surveillance might not be effective to detect outbreak,it is necessary to explore more sensitive and synthetical sur veillance measures in practice.