An epidemiological study on an outbreak of viral meningitis caused by ECHO virus 30 in Lianyungang

Objective This study was designed to analyze the epidemic characteristics,risk factors and etiology of a viral meningitis outbreak in Lianyungang City,Jiangsu Province in 2006.Methods The cases were investigated using uniform epidemiological questionnaire and the data of viral meningi- tis in-patients throughout the city since 2004 were collect for epidemiological and clinical analysis. The risk factors were analyzed with 1:2 matched case-control study.24 samples of cerebrospinal fluid (CSF)were sent to Jiangsu Provincial CDC for virus isolation.Results The epidemic of viral menin- gitis presented as sporadic cases throughout the city from 2004 to 2005;968 cases were detected from January to July in 2006 with a rise of epidemic in June(when outbreak occurred in 1 county and 2 districts)and a peak in July(when 473 new cases presented which accounted for 48.86% of all cases in the city).The predominant population involved in the epidemic were children under the age of 15,ac- counting for 94.44% of all cases;males were more than females with the M/F ratio being 2.65:1.The main clinical manifestations were fever,headache,vomiting,positive meningeal irritatation sign and an increase of nucleated cells in CSF.The habits of washing hands before dining and eating fresh fruits could be protective factors,indicating that the epidemic of this disease is associated with unhygienic habits.PCR detection of 23 CSF samples showed 16 of Echovirus 30 positive.Conclusion Echo virus 30 was responsible for the outbreak of viral meningitis in Lianyungang City(including 1 county and 2 districts)in 2006,unhygienic habits could be the risk factor of the epidemic of this disease.