RESUMO
OBJECTIVE: To understand the epidemiological, clinical and etiological characteristics of an Echovirus type 6 meningitis outbreak in Jinzhai county, Liu'an city in Anhui, and to find out the proper way in controlling the aseptic meningitis outbreak. METHODS: A surveillance system for aseptic meningitis was established in Jinzhai to confirm the case definition. Stool or cerebrospinal fluid (CSF) specimens from some cases were collected for entero-viruses isolation and identification. Case-control study was conducted. The case group involved patients while the controls would include: patients' classmate with same gender and the age difference was not over one year. Neutralization antibody in serum specimens were collected and tested in cases and in healthy people. RESULTS: 105 cases were distributed in 17 of the 30 towns in Jinzhai county while 41.0% of the cases were in Banzhuyuan town with an incidence rate of 203/10(5). Cases were clustered by school and classroom with age ranging from 3 to 15 years old and the highest as 10.9/10(5) in the 6 to 10 group. The incidence in males was 24.2/10(5) compared to 8.4/10(5) in females. The main clinic characteristics of cases were: fever, headache and vomiting. Echovirus type 6 from 25 of the 72 CSF samples (35%) was isolated. When comparing the cases group with control group, the OR of drinking home-made beverages was 4.1 (95% CI: 1.4-12.0), especially the beverages sacked by plastic bag: 3.3 (95% CI: 1.3-8.8). 6 out of 7 workers engaging in producing home-made beverages were detected to have carried Echovirus type 6 from their stool specimens. The Echovirus type 6 neutralization antibody positive rate in cases (73.5%) was significantly higher than that in 100 healthy people (46.0%) (X2 = 12. 526, P = 0.000). CONCLUSION: This episode of meningitis outbreak was caused by Echovirus type 6. The proportion of drinking home-made beverages, especially the beverages sacked by plastic bag in cases group was higher than in control group.
