[Acute meningitis and encephalitis syndrome surveillance disease burden in four China prefectures]

Objectives: To explore acute meningitis and encephalitis syndrome (AMES) surveillance in 4 China prefectures, to understand the epidemiological features and disease burden of neisseria meningitides (Nm) meningitis, streptococcus pneumoniae (Sp) meningitis, haemophilus influenza type b (Hib) meningitis and Japanese encephalitis and provide evidence for related disease prevention and control. Methods: AMES surveillance were conducted in Jinan, Shandong Province and Yichang, Hubei Province in September 2006, and in 13 districts of Shijiazhuang, Hebei Province and Guigang City, Guangxi Zhuang Autonomous Region in April 2007. Six hospitals in each city were selected as monitoring pilot hospitals to carry out reports of suspected cases of acute meningitis and encephalitis, case investigation, blood specimens and cerebrospinal fluid specimen collection, anti-JEV IgM antibody enzyme-linked immunosorbent assay, Nm, Sp and Hib culture and polymerase chain reaction detection, etc. According to the age group, the incidence of bacterial meningitis and Japanese encephalitis in local residents <20 years old was estimated. Results: From 2006 to 2013, a total of 19 423 surveillance cases were reported in four cities, of which 11 071 (56.99%) were reported in the pilot hospitals. Of the 11 071 cases, 5 315 were tested for bacteriology and 9 180 were tested for anti-JEV IgM antibodies. Among the bacteriological tests, 176 cases were positive, including 75 cases of Nm positive, 91 cases of Sp positive and 10 cases of Hib positive. The incidence of three bacterial meningitis is estimated for people under 20 years old, with estimated incidence of Nm, Sp and Hib meningitis in children <5 years old was 0.46/100 000-0.71/100 000, 0.34/100 000-0.83/100 000 and 0.32/100 000-0.57/100 000 respectively; the estimated incidence of Nm and Sp meningitis in children aged 5-9 years was 0.59/100 000-1.14/100 000 and 0.50/100 000-1.66/100 000 respectively. In 732 cases of positive JE cases, the positive detection rates of <5 years old, 40-49 years old and ≥50 years old were 9.51% (95/999), 28.09% (66/235) and 33.85% (130/384), respectively. The estimated annual incidence rate of JE was 0.12/100 000-0.79/100 000.ratio of cases 1.19∶1. Most of cases (27.30%) were children and adolescents aged 5-14 years and those (26.84%) aged over 45 year. Conclusion: The study found that primary and secondary school students are the key population of Nm meningitis, suggesting that it is necessary to explore the enhanced immunization study of meningococcal vaccine in this population; Sp has the possibility of occurrence in all age groups; <5 years old children are the main population of Hib meningitis.