2013—2018年广州市学校和托幼机构水痘聚集性疫情的流行病学分析

Epidemiological analysis on clustering epidemics of varicella in schools and kindergartens in Guangzhou City,2013-2018

目的分析2013—2018年广州市学校和托幼机构水痘聚集性疫情的流行病学特征,为水痘防控措施的制定提供依据。方法收集2013—2018年广州市各区上报的学校和托幼机构报告的水痘聚集性疫情,对其进行描述性分析。结果2013—2018年广州市共报告学校、托幼机构水痘聚集性疫情1876起,平均罹患率为0.63%。发病高峰分别为3—6月和10月至次年1月,托幼机构、小学、中学、高校和其他机构分别占28.04%、56.45%、13.33%、2.19%;城市、城郊、郊区之间的平均每起疫情病例数、波及班级数、罹患率和疫情持续时间均有统计学差异(P<0.05),城市上述指标均小于城郊和郊区;是否开展应急接种疫情间的波及班级、罹患率和疫情持续时间均有统计学差异(P<0.05),已开展应急接种疫情的以上指标均小于未开展应急接种的疫情。结论托幼机构、小学是水痘聚集性疫情的防控重点场所,需加强此类机构的防控工作。应急接种可减小疫情规模和缩短疫情持续时间。建议在发生水痘聚集性疫情的托幼机构或学校尽早开展应急接种。

Objective To analyze the epidemiological characteristics of clustering epidemics of varicella in schools and kindergartens in Guangzhou City from 2013 to 2018 so as to provide a basis for formulating varicella prevention and control strategy.Methods Descriptive epidemiological methods were used to analyze the data about clustering epidemics of varicella reported by each district of Guangzhou City in 2013-2018.Results A total of 1,876 clustering epidemics of varicella occurring in schools and kindergartens were reported in Guangzhou City from 2013 to 2018,with the average attack rate of 0.63%.The incidence peak occurred during March-June as well as from October to January of next year.The proportions of clustering epidemics of varicella occurring in schools,kindergartens,primary schools,middle schools,and colleges&other institutions accounted for 28.04%,56.45%,13.33% and 2.19%,respectively.Statistically significant differences were found in the average number of cases per outbreak,the number of classes involving into outbreaks,the attack rate and outbreak duration amongst the urban,suburban and rural areas(all P<0.05).The above-mentioned indexes were all lower in the urban area than in the suburban and rural areas.There were statistically significant differences in the number of classes involving into outbreaks,the attack rate and outbreak duration between conducting and not conducting contingency vaccination(all P<0.05).The above-mentioned indexes were all lower in outbreaks with contingency vaccination than in outbreaks without contingency vaccination.Conclusions Kindergartens and primary schools are the key units for prevention and control of clustering epidemics of varicella;and hence,strengthening the prevention and control work in these units are necessary.Contingency vaccination can minimize the scale of outbreak and shorten the duration of outbreak.The results suggest that contingency vaccination should be launched as soon as possible in kindergartens and schools with clustering epidemic of varicella.