湖北省一例脊髓灰质炎疫苗高变异株病例的流行病学调查分析

目的 阐述湖北省1例脊髓灰质炎(脊灰)疫苗高变异株病例的流行病学调查与处理情况。 方法 对疫情开展病例个案调查、实验室检测、病毒传播风险评估,对病例进行消毒、随访,由省级AFP病例专家诊断小组会诊并做出临床分类。 结果 2013年5月,湖北省发生1例Ⅲ型脊灰疫苗高变异株病毒病例,经省级和国家脊灰实验室在对病例所分离到的脊灰病毒进行核苷酸序列测定时,与Sabin疫苗株比较发现VP1区有8个(0.88%)核苷酸变异。患儿总共口服了2剂次脊灰减毒活疫苗(oral poliomyelitis vaccine, OPV),未规范服苗。 结论 该病例最终分类诊断为非AFP病例。各级卫生部门采取了包括主动搜索急性弛缓性麻痹(acute flaccid paralysis, AFP)病例、开展查漏补种OPV等措施,有效控制了疫情的扩大和蔓延。

Epidemiological survey of a case caused by highly variant vaccine-derived poliovirus in Hubei

Objective To understand the epidemiological characteristics of a case caused by highly variant vaccine derived poliovirus in Hanchuan, Hubei province, in May 2013. Methods The case survey, virus excretion monitoring, laboratory examination and transmission risk assessment were conducted and the case was isolated and followed up. Results The isolate from the case was identified as highly variant vaccine-derived poliovirus type Ⅲ(8nt, 0.88%) by nucleotide sequencing in provincial and national polio laboratory, respectively. The case had received irregular 2 dose oral polio vaccine (OPV) immunization. Conclusion The case was finally diagnosed with non-acute flaccid paralysis (AFP) and no further transmission occurred due to strict prevention and control measures, including active search for AFP cases and supplementary immunization of OPV among the local children.