2018年盘锦市大洼区流行性乙型脑炎暴发疫情的流行病学分析

Epidemiological analysis of epidemic outbreak of epidemic encephalitis B of Dawa District in Panjin City in 2018

目的分析2018年盘锦市大洼区流行性乙型脑炎(简称乙脑)暴发疫情的流行病学特征,为制定防控对策提供依据。方法收集整理2018年乙脑暴发疫情的传染病疫情监测信息、患者的流行病学调查资料、随访资料及1971~2017年大洼区的乙脑发病历史资料。采用诱蚊灯法对患者住宅楼道、农村平房院内及牲畜棚蚊媒密度及种类进行监测。结果2018年9月10日~10月10日,盘锦市大洼区暴发乙脑疫情,确诊病例16例,发病率为3.60/10万,病死率为25.00%。男、女各8例,40岁以上病例12例(75.00%),职业以农民为主共8例(50.00%)。疫情累及6个街镇,其中田家街道最多,有6例(37.50%)。发病时间集中在2018年8月末至9月中旬,8月3例(18.75%),9月13例(81.25%)。患者发病后中位就诊时间为0.5 d,发病后中位诊断时间为8 d。1例采集脑脊液,15例采集血清,做乙脑病毒IgM抗体检测,阳性率为100.00%。9例(56.25%)无乙脑疫苗接种史,7例(43.75%)接种史不详。蚊虫密度最低0.5只/(灯·h),最高22.5只/(灯·h),中位数为3.8只/(灯·h)。城区的疫点共7个点;农村的疫点共18个点,其中17个点(94.44%)监测到三带喙库蚊,共诱捕了912只蚊子,其中三带喙库蚊247只(27.08%)。结论盘锦市大洼区已经连续17年无乙脑疫情,此次暴发疫情以成年人患者增多为特点。开展成年人接种乙脑疫苗,适龄儿童查漏补种,防蚊灭蚊,监控动物疫情,同时加强医疗机构早期诊断和治疗能力,是防控乙脑疫情的关键。

Objective To analyze the epidemiological characteristics of epidemic outbreak of epidemic encephalitis B of Dawa District in Panjin City in 2018,so as to provide basis for formulating prevention and control strategies.Methods The epidemic surveillance information,epidemiological investigation data and follow-up data of the epidemic of epidemic encephalitis B in 2018 and the historical data of epidemic encephalitis B in Dawa District from 1971 to 2017 were collected.Mosquito density and species were monitored by trap lamp method in residential corridors,rural cottage courtyards and livestock shed.Results From September 10 to October 10,2018,there was an outbreak of epidemic encephalitis B in Dawa District of Panjin City,16 confirmed cases with a morbidity of 3.60/100000 and a fatality rate of 25.00%.There were 8 males and 8 females,12(75.00%)were over 40 years old,and 8(50.00%)were peasants.Six towns were affected by the epidemic,of which Tianjia Street had a maximum of 6 cases(37.50%).The onset time was concentrated from late August to mid-September 2018,with 3 cases(18.75%)in August and 13 cases(81.25%)in September.The median visiting and diagnostic time were 0.5 and 8 days after onset,respectively.One case collected cerebrospinal fluid and 15 cases collected serum for detection of epidemic encephalitis B IgM antibody,the positive rate was 100.00%.Nine cases(56.25%)had no history of epidemic encephalitis B vaccination,and seven cases(43.75%)had unknown vaccination history.The lowest density of mosquitoes was the 0.5/(lamp·h),the highest was 22.5/(lamp·h),and the median was 3.8/(lamp·h).There were 7 epidemic spots in urban area,and 18 epidemic spots in rural area.Among them,17(94.44%)were detected with Culex tritaeniorhynchus,and 912 mosquitoes were trapped,of which 247(27.08%)were Culex tritaeniorhynchus.Conclusion There has been no epidemic of epidemic encephalitis B in Dawa District for 17 consecutive years.This outbreak is characterized by an increase in adult patients.It is the key to prevent and control the epidemic of epidemic encephalitis B by vaccinating adults,detecting and replanting children of appropriate age,preventing mosquitoes and killing mosquitoes,monitoring the epidemic situation of animals,and strengthening the ability of early diagnosis and treatment of medical institutions.