托幼机构健康儿童EV71和CoxA16隐性感染的现况调查及危险因素分析

目的为了解肠道病毒71型（EV71）和柯萨奇病毒A组16型（CoxAl6）在深圳市幼儿园健康儿童中的隐性感染情况，进一步探讨儿童手足口病（HFMD）隐性感染的危险因素。方法采用酶联免疫（ELISA）法检测某幼儿园所有健康儿童血清中抗EV71和CoxAl6的IgM抗体水平，同时采用病例对照研究分析EV71和CoxAl6病毒隐性感染的危险因素。结果调查的350名健康儿童中，32名儿童感染了EV71或CoxAl6病毒，隐性感染率为9．1％，其中CoxAl6病毒感染率为7．4％，EV71病毒感染率为3．1％，同时感染CoxAl6和EV71两种病毒的感染率为1．4％；暴发班级的感染率为17．0％，非暴发班级的感染率为6．5％。每天洗手3次及以上（OR=0。40，95％CI：0．19～0．85）、洗手使用清洁剂（OR=0．33，95％CI：0．16—0．68）为EV71、CoxAl6病毒隐性感染保护因素；所在班级出现HFMD的聚集性病例（OR=3．80，95％CI：1．81—7．99）和儿童有咬玩具、咬手指习惯（OR=2．29．95％CI：1．06。4．92）为EV71、CoxAl6病毒隐性感染危险因素。结论隐性感染在一定程度上影响着HFMD的流行，加强病人的密切接触者管理和宣传教育，尽可能降低隐性感染者的比例，对控制HFMD的暴发及流行有着重要的意义。

A prevalence survey and analysis of risk factors on subclinical infection of the EV71 and CoxA16 in healthy children in nurseries

Objective To investigate subclinical infection of enterovirus 71 （EV71 ） and coxsackievirus A16 （CoxA16） in the healthy children from the nurseries in Shenzhen and analyze the risk factors of subclinical infection of hand-foot-and- mouth disease （HFMD）. Methods Antibodies against EV71 and CoxA16 were measured by ELISA method. A case- control study was performed to analyze the major risk factors of subclinical infection of HFMD. Results The positive rate of subclinical infection of HFMD was 9.1%（32/350）. The positive rates of IgM antibodies against CoxA16 and EV71 were 7.4% and 3.1%, respectively. The positive rate of the CoxA16 and HFMD infection was 1.4%.The subclinical infection rates of HFMD in the classes with HFMD outbreaks and the classes without HFMD outbreaks were 17.0% and 6.5%, respectively. The case-control study analysis showed that washing hands three times a day or more（ OR=0.40,95% CI ： O. 19-0.85） and washing hands using a cleaning agent （OR=0.33,95%CI ： O. 16-0.68） were protective factors. In the classes with HFMD outbreaks （OR=3.80,95% CI ： 1.81-7.99 ） and biting toys or fingers （OR=2.29,95% CI ： 1.06-4.92） were the risk factors concerned with the subclinical infection of HFMD. Conclusions Subclinical infection has an effect on the incidence of HFMD. Strengthening of the management and public education are important in the control of the outbreak and prevalence of HFMD.