许昌市2007—2017年流行性乙型脑炎流行特征

Epidemiological characteristics of Japanese encephalitis in Xuchang, 2007-2017

目的了解许昌市2007-2017年流行性乙型脑炎的免疫接种、诊断与治疗、临床分型与愈后,以及流行病学特征,为科学制定防控措施提供依据。方法采用描述流行病学方法进行分析。结果2007-2017年许昌市累计报告流行性乙型脑炎40例,年均报告发病率为0.09/10万。年报告发病率波动于0.00/10万~0.21/10万之间,并于2009和2010年、2016年出现两个发病率高峰,总体呈现下降趋势。病例主要分布在农村地区(97.50%),以15岁以下儿童为主(95.00%),以散居儿童和幼托儿童为主(65.00%)。时间分布在7-10月,8月为发病最高峰(55.00%),有严格的季节性。调查发现,许昌市历年常规免疫接种率均未达到100.00%,且有2.50%病例完成乙脑疫苗全程接种后发病,存在免疫空白和免疫失败情况。本地诊断率低(仅5.00%),发病至诊断时间间隔较长,M(P25-P75)为5.5(4-9)d。临床愈后不佳,病死率为2.50%,后遗症发生率为35.00%。结论近年来,许昌市流行性乙型脑炎维持在较低报告发病率水平。但仍存在免疫空白和免疫失败、重症和极重症病例构成比高、临床后果严重、本地医疗机构诊断率低和病人发病与诊断时间间隔较长等问题,应进一步加强预防接种、防蚊灭蚊、环境治理、健康教育和专业技术人员培训等综合性预防控制措施,减少乙脑疫情的发生和流行,提高及时诊断率和救治成功率。

Objective To understand the epidemic characteristics,diagnosis,treatment,clinical classification,prognosis and immunization status of Japanese encephalitis (JE)in Xuchang City from 2007 to 2017,so as to provide the evidence for formulating prevention and control measures.Methods The data of JE in Xuehang from 2007 to 2017were collected and analyzed by the descriptive epidemiological method.Results Totally 40 cases were reported in Xuchang City from 2007 to 2017,and the average annual incidence rate was 0.09/105.The annual reported incidence fluctuated between 0.00/105 and 0.21/ 105,and there were two incidence peaks from 2009-2010 and in 2016.The reported incidence of JE overall showed a downward trend.The cases of JE were distributed mainly in rural areas (97.50%).Most of the cases were children under 15 years old (95.00%),and most of the cases were scattered children and preschool children(65.00%).All the cases happened from July-October.JE had a strict seasonal character,which reached the peak in August(55.00%).The survey found that the situation of immune gap and immune failure of JE vaccine existed.The routine immunization coverage rate of JE vaccine over the years did not reach to 100.00%and 2.50%cases were whole-range immunized.The local diagnosis rate was low (5.00%), and the time interval between the onset and the positive diagnosis was long (M (P25-P75)was 5.5(4-9)days).The mortality rate was 2.50%,and the incidence rate of sequelae was 35.00%.Conclusions In recent years,the reported incidence rates of JE are low.Because there are the factors of immune gap and immune failure,the higher proportion of severe and extremely severe cases,poor prognosis,low local diagnosis rate,and long-time interval between the onset and the positive diagnosis,we should strengthen the comprehensive prevention and control measures,including the prophylactic vaccination,mosquito control,environmental governance,health education,and training of professionals,so as to reduce the incidence of JE and increasethe rates of timely diagnosis and treatment success.