Epidemiological analysis of Japanese encephalitis in Kai County of Chongqing Municipality

Objective The study was conducted to analyze the epidemiological characteristics, clinical manifestations,laboratory findings of Japanese Encephalitis in Kai County.Methods The epidemiological and clinical data of Japanese encephalitis in Kai County from June to August 2006 were collected lot analysis.Results The patients' age ranged from six months to 18 years.The epidemic lasted from June 17 until August 30,and the cases distributed among 30 towns without family cluster.62.12% of the patients had no vaccination history.Their symptoms included fever, convulsions,and coma.As to the signs,neck stiffness accounted for 84.85%,positive Kernig sign 62.12%,and positive Brudzinski's sign 69.70%.The average total white cell count was 17.010~9/L,and neutrophil count 8.410~9/L.In early detection of serum,the positive rate of Japanese encephalitis IgM antibody was 75%.Five patients died after combined therapy,the fatality rate being 7.58%.Conclusion Strict seasonal and age characteristics were found in the highly sporadic Japanese Encephalitis epidemic.Affected cases lived with poor sanitation,where also lived the media,mosquitoes. Insufficient epidemic prevention in mountain areas and low immunization rate were the main factor causing the epidemic.