2007年上海市某小学水痘爆发的流行病学调查  

An Epidemiological Study on the Outbreak of Chickenpox in Elementary School in Shanghai in 2007

作　　者：徐敏钢 黄瑾[1] 吴益生[1] 杨其帆[1] 田国栋[1] 敖建军[1] 吴霞[1] 华瑞珏 

机构地区：[1]上海市闸北区疾病预防控制中心,上海200072

出　　处：《中国疫苗和免疫》2008年第6期516-520,共5页Chinese Journal of Vaccines and Immunization

摘　　要：目的通过调查上海市某小学的水痘爆发，分析水痘的传播途径和流行过程，评价水痘减毒活疫苗（Varicella Attenuated Live Vaccine，VarV）接种现状和保护率，探索水痘免疫对策。方法2007年10月29日～2008年1月19日，对该校所有在校学生进行水痘发病问卷调查，同时查询VarV预防接种记录，分析爆发的危险因素，计算疫苗保护率。结果1172名学生中，86．3％（1012／1172）在爆发前无水痘患病史，66．8％（676／1012）有VarV接种史。本次水痘发病73例，共形成3次发病高峰。病例主要分布在3～5年级，1、2年级无水痘发病，且VarV接种率较高[分别为85．3％（139／163）和78．8％（152／198）]。无接种史的易感者水痘罹患率非常显著地高于有接种史者（χ^2=23．45，P〈0．001），VarV保护率是68．5％（95％可信限为54．5％～75．5％）。保护率随接种时间延长而明显下降（χ^2趋势=4．131，P=0．0421）。46．6％（34／73）的患者未能及时隔离，具有传播可能性。结论低接种率、免疫时间较长和缺乏及时的报告隔离制度，是此次水痘爆发的主要危险因素。提高中、高年级小学生VarV接种率，深入评价免疫方案，改善水痘监测系统，对预防水痘爆发具有重要意义。Objective An investigation to the outbreak of chickenpox in an elementary school in Zhabei District in Shanghai was carried out to analyze the route of transmission and the epidemics, to evaluate the coverage of varicella vaccination and vaccine effectiveness, to find out the strategies for varicella vaccination. Methods The duration of outbreak was from October 29,2007 to January 19,2008. Questionnaire survey conducted to all the students in the school during the outbreak. Individual vaccination records were reviewed as well. The distribution of chickenpox cases in different age group, gender, grade, class and time of onset were described,and vaccination history, the attendance of school buses were analyzed to find the possible route of transmission. The coverage of previous varicella vaccination and vaccine effectiveness were calculated. Results Among 1172 students, 1012（86. 3%）had no history with chickenpox. 676（66. 8%）of the students had been vaccinated before the outbreaic In total, 73 chiekenpox cases were identified, which formed the three peaks of the outbreak. Cases were found in grade 3 to 5,no cases in grade I and 2,and the coverage of vaccination in grade 1 and 2 were 85. 3% （139/163） and 76.8% （152/198） respectively,higher than that in grade 3～5. The attack rate in non-vaccinated students was much higher than those vaccinated（χ^2=- 23. 435, P〈0. 001）. Vaccine effectiveness was 65% （95% confidence interval： 54. 5 % -- 75.5%）. The attack rate of ehickenpox increased as the duration of inoculation prolonged（χ^2趋势 =4. 131, P=0. 0421）. Of the 73 chickenpox cases,46. 6M （34/73） didn＇t be isolated within one day, and they were the possible infectious sources. Conclusions Low coverage of varicella vaccination,long duration of vaccination and lack of timely reporling and isolation policies were the main risk factors of outbreak. It is important to enhance coverage of varicella vaccination among students at high-grade of elementary schools, assess the scheme of va

关 键 词：水痘 爆发 水痘减毒活疫苗 预防接种 

分 类 号：R511.5[医药卫生—内科学] R186[医药卫生—临床医学]