宁波市2010年9起水痘爆发疫情分析及水痘病原学研究

Epidemiological Analysis of 9 Cases of Varicella Outbreak and Etiological Research in Ningbo Municipal

目的了解宁波市2010年9起水痘爆发疫情的流行病学和病原学特征。方法根据宁波市2010年全国突发公共卫生事件报告管理系统和疾病监测点进行实时流行病学调查,收集数据并统计分析。同时对部分临床诊断水痘病例采集疱疹液标本,采用人胚肺成纤维细胞(Human fetal lung fibroblast cells,MRC-5细胞)进行水痘-带状疱疹病毒(Varicella-zoster Virus,VZV)分离,并提取脱氧核糖核酸进行聚合酶链反应,对扩增产物测序,分析其基因型别。结果宁波市2010年共发生9起水痘爆发疫情,罹患146例,平均罹患率1.79%(以校为单位)。以2010年11、12月报告的突发公共卫生事件起数最多,有9个县(市、区)报告了爆发疫情,发病年龄以7～12岁小学生为主。146例水痘中,有水痘减毒活疫苗(Varicella Attenuated Live Vaccine,VarV)接种史的63例,占病例总数的43.15%。15例患者VZV分离阳性,其中13例VZV为J型,2例为M1型。结论宁波市2010年水痘爆发疫情主要发生在冬春季节,在学校集体单位,J型VZV为宁波市目前流行的主要毒株,但也有M1型VZV的局部爆发。应加强中小学及托幼机构人群的VarV接种,预防控制水痘疫情。

Objective To describe the epidemiological characteristic of outbreak infection of varicella, and to find out the genotype of the prevalent varicella-zoster virus （VZV） in Ningbo municipal. Methods The data collected from the national public health emergencies reporting management system and provincial disease surveillance point system. Meanwhile herpes specimen were collected from clinically diagnosed cases, and genotypes of varicellazoster virus were determined by polymerase chain reaction（PCR） technique. Results 9 outbreaks of 146 cases occurred in Ningbo municipal in 2010, and attack rate was 1.79% in average. 9 districts reported the outbreaks and more varicella infections were identified at age group of 7 to 12 years old. Among the 146 cases, 63 （43.5%） had vaccinated before getting varicella. 15 VZV strains were isolated and identified as 13 genotype J. and 2 genotype M1. Conclusion The prevalence of varicella was frequently reported in schools and kindergartens during the winter-spring season. Genotype J was the most predominant strain but M1 strain prevelenced in local area in Ningbo municipal. The varicella prevention and control among schools and kindergartens should be strengthened by propaganda and vaccination.