深圳市某小学一起水痘暴发疫情的现场流行病学调查

目的调查深圳市某小学一起水痘疫情的流行特征,探讨其危险因素。方法按照病例定义搜索病例,描述疾病的三间分布并开展危险因素现场调查分析。结果 2012年11月30日至2013年1月9日共搜索到符合病例定义的病例22例,首例病例发病时间为11月15日,未隔离;疫情报告日期和发病高峰为11月30日;对新发病例严格执行隔离措施,末例病例为12月19日。17例病例为一年级（6）班学生,该班罹患率为33.3%（17/51）,另有4例其它班级病例与该班首发病例在同一午托室休息。一年级（6）班未接种组的罹患率为100%（4/4）,接种组为33.3%（13/39）,水痘疫苗的4年保护率为66.7%。结论未尽早隔离首发病例、及时报告是此次疫情的主要危险因素,及时发现新发病例、严格执行隔离措施可有效控制疫情。疫苗保护效果还需深入开展评价。

Field epidemiological investigation on a varicella outbreak in a school of Shenzhen

Objective To study the characteristics of a varicella outbreak in a premier school of Shenzhen and explore the risk factors..Methods Patients were collected according to the case definition.By means of field epidemiologic investigation,the characteristics and risk factors were explored. Results From 30 Nov. 2012 to 9 Jan. 2013,22 cases were confirmed. The first case of outbreak was on 15 Nov.,but not was isolated. The outbreak was reported until 30 Nov.2012,which was the incidence peak. The highest attack rate of 33.3%（17 / 51） was noted in class 6 grade 1,other 4cases were in the same afternoon child-care room. The attack rate of the non-vaccinated students was 100%（4 / 4）,and of vaccinated students was 33.3%（13 / 39）,with vaccine effectiveness of 66.7%.Conclusions There was an outbreak of varicella in a school from 15 Nov..2012 to 9 Jan..2013,the main risk factors included that the first case was not quarantined and reported early.Early finding of the cases and strictly conducting isolation could effectively control the outbreak..The effectiveness of vaccination should be assessed in future.