水痘减毒活疫苗高覆盖率的托幼机构水痘爆发调查  

A Varicella Outbreak in a Highly Vaccinated Kindergarten Population

作　　者：富继业[1,2] 史如晶[2] 马天薇[2] 王菊光[2] 刘民[1] 

机构地区：[1]北京大学公共卫生学院,北京100191 [2]北京市海淀区疾病预防控制中心,北京100094

出　　处：《中国疫苗和免疫》2015年第1期80-83,118,共5页Chinese Journal of Vaccines and Immunization

摘　　要：目的通过对北京市海淀区某托幼机构2010年发生的水痘爆发疫情调查,获得水痘减毒活疫苗（Varicella Attenuated Live Vaccine,VarV）的有效率及其影响因素,为VarV接种提供参考。方法对该托幼机构水痘爆发疫情进行流行病学描述,结合《北京市水痘监测方案》中水痘病例个案调查表、儿童水痘患病史和VarV接种史调查问卷,计算未接种和接种过VarV儿童的水痘罹患率、疫苗的有效率,并分析影响VarV效果的因素。结果 2010年3月10-29日,该托幼机构累计发生水痘12例,其中10例（83.33%）有VarV免疫史。首例患者,5岁,有VarV接种史,症状较轻（皮疹〈50个）。全部150名儿童中,既往无水痘患病史儿童144名,其水痘罹患率为8.33%（12/144）,VarV接种率为93.75%（135/144）,Var V对所有水痘预防的有效率为66.67%[95%可信区间（Confidence Interval,CI）：19.13%-100%],对中度水痘预防的有效率为86.67%（95%CI：54.78%-100%）;〈15月龄接种VarV儿童出现突破病例是≥15月龄接种儿童的5.310倍（95%CI：1.171-24.076）。结论有VarV接种史儿童发生水痘突破病例后,与普通水痘一样具有传染性。高水平的单剂VarV覆盖率可有效降低水痘罹患率,但无法预防水痘爆发。低月龄接种VarV是儿童发生水痘突破病例的危险因素。Objective We investigated a varicella outbreak in a kindergarten in Haidian district to determine vaccine effectiveness （VE） and factors influencing varicella vaccine, in order to provide evidence for varicella vaccination. We sought to determine the rate of varicella vaccination, describe the outbreak, calculate vaccine effectiveness （VE） and examine risk factors for vaccine failure. Methods We used standardized question- naire from the Beijing Varicella Surveillance Plan to determine children＇s medical and vaccination histories, to calculate the incidence rate and VE among unvaccinated population and vaccinated population in the kin- dergarten, and to analyze the factors influencing VE. Results A total 12 cases occurred during the period of March 10-29, 2010. Ten of the 12 （10/12, 83. 33% ） children had previously received varicella vaccine. The index case was 5 years old and had mild varicella （ 〈50 lesions）. Among a total of 150 children, 144 had no prior history of varicella disease. Among these children, there were 12 varicella cases, for an incidence rate of 8.33%. A total of 135 children （135/144, 93.75% ） had received a dose varieella vaccine before the outbreak. VE was 66.67% [95% confidence interval （CI） ：19. 13% - 100% ] for any severity of varieella, and VE was 86.67% （95% CI： 54. 78% - 100% ）for moderately severe varicella. Children who had been vac- cinated at 〈 15 months of age were at greater risk for vaccine failure compared with those vaccinated 〉I 15 months of age （Relative Risk： 5. 310, 95% CI：I. 171 -24. 076）. Conclusions Breakthrough infection amongvaccinated, healthy children can be as infectious as varicella in unvaccinated persons. High vaccination coverage with one dose of varicella vaccine is effec- tive in reducing varicella incidence, but not suffi- cient to prevent an outbreak. Vaccination at a young age was a risk factor for varicella breakthrough cases,

关 键 词：水痘 爆发 水痘减毒活疫苗 疫苗有效率 

分 类 号：R186[医药卫生—流行病学] R511.5[医药卫生—公共卫生与预防医学]