Objective To assess the new edition of WHO Japanese Encephalitis (JE) Surveillance Standards (WHO Standards) based on syndrome surveillance data and to provide field evidence regarding the standards. Methods Based on syndrome surveillance data, acute encephalitis syndrome (AES) case was categorized, according to the WHO Standards. A cohort study was applied to estimate the AES definition set in the Standard and relative risk was computed to estimate the existence and intensity of statistical correlation between AES and JE cases. Percentage of attributable risk was counted to describe the coverage of AES for JE cases in the studied population. Sensitivity,specificity, Youden index and positive predictive value of AES components were calculated for the purpose of identifying the clinical values under the screening program. Results 1424 suspected cases were evaluated in the surveillance program and 1396 cases with ELISA result, of which 109 positive cases were detected. According to the "standardized" classification, a total of 706 cases in line with AES case deftuition, were categorized into 83 cases of JE, 425 cases of AES unknown and 198 cases of AES other agent. In the cohort study,a relative risk of 4.62 (95% CI:2.80-7.63 ) and the percentage of attributable risk as 78.35% (95% CI: 64.25% -86.89% ) were observed. Conclusion The AES definition for JE was significantly effecting on the screening programs and a strong correlation strength was observed in the study. AES syndrome could cover most of the JE cases. "Convulsions",with appreciative screening value, was recommended to be involved into the new version of the WHO Standards.

OBJECTIVETo estimate disease burden and epidemiological characteristics of acute meningitis/encephalitis, and provide the basis for the disease control strategy development.

METHODSA syndrome surveillance system was established in Guigang city with a population of 5 020 000. For the suspected cases, serum and CSF were collected, and bacterial culture, latex agglutination test, real-time PCR and ELISA tests were carried out. All involved cases were identified to 6 categories according to WHO case definition.

RESULTS1424 suspected cases were evaluated in a surveillance of 30 months, yielding the incidence, mortality and mortality of 11.35/100 000 (1424/12 546 500 person years), 0.43/100 000 (54/12 546 500 person years), 3.79% (54/1424) respectively. A total of 103 and 51 cases were confirmed for JE, bacterial meningitis, with a incidence of 0.82/100 000 (103/12 546 500 person years), 0.41/100 000 (51/12 546 500 person years). 96.10% (99/103) of JE cases and 37.30% (19/51) bacterial meningitis cases occurred in < 10 years old children and < 5 years old children. A clinical misdiagnosis rate of 19.42% (20/103) and 15.69% (8/51) were observed for JE and bacterial meningitis.

CONCLUSIONAcute encephalitis, meningitis syndrome can cause a higher burden of disease, of which the main components of viral encephalitis. Most of syndrome is occurred in summer and autumn, mainly reported in children of younger than 10 years old. A quite misdiagnosis would be made among meningitis and encephalitis syndrome cases.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; China ; epidemiology ; Encephalitis, Viral ; epidemiology ; Female ; Humans ; Infant ; Male ; Meningitis, Bacterial ; epidemiology ; Meningoencephalitis ; epidemiology ; microbiology ; prevention & control ; virology ; Middle Aged ; Seasons ; Young Adult