海南省2009年流行性乙型脑炎监测分析

Surveillance of epidemic encephalitis B in Hainan Province in 2009

目的了解海南省流行性乙型脑炎(简称乙脑)流行规律,为制定乙脑防制策略提供依据。方法按照《海南省流行性乙型脑炎监测方案》监测报告病例,采集监测病例血清标本,在国家乙脑监测点东方市进行媒介和宿主监测,人和宿主血清标本均用ELISA法分别检测疑似病例乙脑IgM抗体和宿主IgG抗体;采用容量比例概率抽样法抽查全省乙脑疫苗接种率。监测结果用SPSS13.0进行统计分析。结果海南省2009年共监测报告乙脑疑似病例111例,市县区报告疑似病例的有19个,覆盖率86.36%;采集病例血清标本110例,脑脊液标本33例,经血清学和脑脊液确诊病例11例,发病率为0.12/10万,疑似病例24h及时报告率为92.79%,病例分布在7个市县区,占总市县数的31.82%,病例呈高度散发;6月上旬峰值最高,占病例总数45.45%;病例以2岁以下儿童发病率最高,为1.85/10万,病例男女比为4:7;病例中无免疫史和免疫史不详者占72.73%。媒介监测显示三带喙库蚊的密度最大,为40.96只/人工.h,三带喙库蚊以畜房密度最高,为72.13只/人工.h。宿主猪血清阳性率30.91%。抽查乙脑基础免疫接种率97.80%,高于2008年的95.68%,(χ2=18.27,P<0.001),加强免疫接种率98.68%,高于2008年的93.31%(χ2=41.01,P<0.001)。结论海南省仍为乙脑流行区,媒介和宿主广泛存在,确保适龄儿童乙脑疫苗高接种率、高抗体水平,以有效控制乙脑的流行。

Object To analyze the prevalent trend of epidemic encephalitis B in Hainan in 2009. Methods According to the scheme of the surveillance of epidemic encephalitis B in Hainan province, the suspected eases were surveyed and reported. The serum samples were collected in Dongfang City chosen as the natinal monitoring site for surveying host and vectors of encephalitis B virus by using ELISA. The coverage rate of epidemic encephalitis B vaccine was investigated selectively in the end of year with proportion allocation in stratified random sampling. The results were analyzed with SPSS13.0. Results 111 suspected encephalitis B cases were reported from 19 counties and the coverage rate was 86.36%.110 serum samples of the cases were collected （98.20%）. 33 cerebrospinal fluid samples were collected and 11 eases were confirmed by serology and eerebrospinal fluid examination with the incidence of epidemic encephalitis B of 0.12/100 000. 92.79% of all cases were reported timely in 24h. The cases were distributed in 7 counties,occupying 31.82% of total counties. The peak incidence was in early June,the incidence in children under 2 years old was the highest （1.85/100 000）. The ratio of male to female was 4：7. There was 72.73% of cases without vaccination history. The density of Culex tritaeniorhynchus was 40.96/h with the highest density in barn（72.13/h）. The serum positive rate of pig, the host of Culex tritaeniorhynchus was 30.91%; the coverage rate of basic immunization was 97.80% higher than 2008（95.68% ）, showing significant differences between 2009 and 2008（~z=18.27,P〈0.001）,The coverage rate of fortified immunization was 98.68% . Conclusion Hainan province is still prevalent with epidemic encephalitis B, and there are wide range media and host in Hainan. High coverage of vaccination and antibody level can effectively control the epidemic encenhalitis B.