Analysis on Epidemiological Characteristics of Pandemic Influenza A(H1N1-2009) in Hunan Province

Objective To study the epidemiological characteristics of pandemic influenza A(H1N1-2009) in Hunan Province. Methods A descriptive study was used to analyze the H1N1 cases from May 2009 to May 2010,which included both individual information based on China Information for Diseases Control and Prevention and pathogen data,and outbreak situation as well.Meanwhile,the descriptive study was also conducted to analyze three different phase-based sampling investigation of 2010 H1N1 virus infection in Hunan Province. Results Between May 2009 and May 2010,a total of 12,789 H1N1 cases were reported in Hunan Province,with the incidence rate reported as 19.96 cases per 100,000 people.The epidemic highly occurred from September to December,and Changsha, Chenzhou and Yongzhou were the main incidence cities with 89.83/100,000,25.19/100,000 and 21.85/100,000 seperately.Those who aged from 6 to 14 years were the high risk group,accounting for 49.84% with 6,374 cases.Totally,930 H1N1 outbreaks were occurred during the 2-year period.The pathogen monitors showed that during the 45th weeks to the 51st weeks in 2009,a continuously 90% to 100% high proportion of H1N1 in influenza positive specimens was seen. Conclusions The H1N1 influenza epidemic is relatively mild in Hunan Province,infants and children in kindergartens or schools are the key groups for control and prevention of influenza A(H1N1).