INFLUENZA SURVEILLANCE IN HAINAN DURING 2004-2006

[Objective] To understand influenza epidemic and find out virus variance in time, so as to provide scientific evidence for preventing and controlling in Hainan. [Methods] By collecting the surveillance information isolation and identification of virus among the influenza-like case and the investigation of the outbreak in Hainan sentinel hospitals during 2004-2006, and analyzing by the descriptive epidemiology study. [Results] From 2004 to 2006, the percentage of influenza-like illness (11 760 cases) in out-patient department (884 039 cases) was 1.33%. The peak incidence months were April and May. Among the total 516 incidence cases, there were 5 outbreaks, and the attack rate was 5.07%. Throat swab specimens of 1712 patients were collected in influenza-like illness, including 46 strains H1N1 virus, 125 strains H3N2 virus and 63 strains type B, which is the same as the peak season of influenza epidemic. Most outbreaks were caused by H3N2 virus. [Conclusion] Influenza appears all through the year and mostly in the late spring and early summer in Hainan, and infects different especially in group of 5-14 year-old. Most outbreaks happened in schools. The epidemic influenza virus strains were H1N1, H3N2 and type B, of which H3N2 caused more cases. No influenza virus variance and lethal avian influenza virus emerged.