Study on an outbreak of echovirus type 6 of meningitis in Liu'an city, Anhui province / 中华流行病学杂志

ABSTRACT

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSION</b>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.</p>