Epidemiological Characteristic of Influenza Outbreak from 2004 to 2008 in Shiyan City

[Objective]To analyze the etiology and epidemiological characteristics of influenza outbreak from April 2004 to March 2009,provide reference for guiding the prevention and control of influenza.[Methods]The data of investigation and handling of influenza outbreak in 5 years were analyzed by epidemiological surveillance,pathogenic detection and serological test.[Results]During 5 years,31 epidemic outbreaks and 1151 cases were reported.Epidemic situation occurred in the urban area and 5 counties,of which 26 epidemic outbreaks happened in middle and primary schools and 5 epidemic outbreaks happened in technical secondary school.[Conclusion]In 5 years,the influenza outbreak mainly happened in January to May and August to September.The pathogens were H3N2 subtype,HlNl subtype and Victoria of B type of influenza virus.There were winter peak and summer peak of influenza outbreak in Shiyan area.It is indicated that monitoring should be strengthened and immunization coverage rate of influenza among key population should be improved.