Surveillance of acute encephalitis and meningitis in Guangxi autonomous region, China

Objective To learn about the disease burden, clinical and epidemiological characteristics of acute encephalitis and meningitis in Guangxi and provide evidence for the diseases prevention and control. Methods The surveillance system of acute encephalitis and meningitis was established in Guigang municipality to conduct epidemiological survey, sample taking for bacterial pathogens culture, RT-PCR and detection of IgM of 10 viruses by ELISA. The data were entered into the project database and analyzed by SPSS 16.0 software. Results A total of 883 suspected cases including 41 deaths were reported from May 2007 to October 2008 with the case-fatality rate of 4.64%. The annual incidence rate was 11.73/lakh for suspected case, 8.46/lakh for clinical diagnosed case and 4.28/lakh for laboratory confirmed case. The incidence rate of meningitis was 1.16/lakh for clinical diagnosed cases and 0.48/lakh for laboratory confirmed case; and the incidence rate of encephalitis was 7.31/lakh for clinical diagnosed case and 3.80/lakh for laboratory confirmed case. The incidence of encephalitis was significantly higher than meningitis. The incidence rate of encephalitis and meningitis in Guiping city was highest (the laboratory confirmed incidence rate: 5.18/lakh). JE virus related encephalitis mainly occurred in summer. No significant difference was found on the incidence between male and female. The incidence rate in 0-4 years age group was highest (28.44/lakh). The positive rate was 6.93% for blood culture, 3.39% for CSF culture and 6.58% for RT-PCR. The positive rate of IgM of 10 virus by ELISA was 38.41% (10.94% for JE and 27.47% for other virus), Conclusion The incidence of acute encephalitis and meningitis was still high in Guangxi with the cases mainly caused by virus. It is necessary to strengthen the vaccination for the right age children and disease surveillance, especially among the children living separately.