Influenza-associated-excess-hospitalization in children,Wuxi city,Jiangsu province,2005-2010

Objective To estimate the rates due to influenza-associated-excess-hospitalization in children aged 0-14 years in Wuxi city,Jiangsu province in 2005-2010. Methods We collected data on hospitalization due to influenza,pneumonia and other respiratory diseases from fourteen 2nd level or above hospitals in Wuxi,as well as data on influenza virological surveillance in southern China to fit the negative binomial regression models,to estimate the rate on influenza-associated-excess hospitalization. Results During 2005-2010,an average annual hospitalization rate appeared as 91.6‰（79.2‰-99.3‰）. Among the total hospitalization eases,respiratory diseases accounted for 54.2%,while both influenza and pneumonia accounted for 38.1%. The average annual influenza-associated-excess-hospitalization rates due to influenza and pneumonia appeared as 1.28‰（95%CI：0.29‰-4.84‰）,while 2.18‰（95%CI：0.61‰-6.79‰） due to respiratory diseases. In 2009,A（H1N1）pdm induced influenza pandemic caused 993 excess hospitalizations due to influenza/pneumonia and 1 042 excess hospitalizations due to respiratory diseases,with rates as 1.14‰ and 1.20‰ respectively. Conclusion Both seasonal and pandemic A（H1N1）pdm influenza caused considerable burden on hospitalization in children aged 0-14 years in Wuxi. Key words: Seasonal influenza; A（H1N1）pdm; Excess hospitalization; Negative binomial regression; Children