中国2001～2013年疫苗衍生脊髓灰质炎病毒及病例流行病学特征分析

目的分析中国（未包括香港、澳门特别行政区和台湾地区，下同）实现无脊髓灰质炎（脊灰）目标后，疫苗衍生脊灰病毒（Vaccine—derived Poliovirus，VDPV）的发生情况。方法分析31个省（自治区、直辖市，下同）报告的急性弛缓性麻痹（Acute Flaccid Paralysis，AFP）病例数据库、中国疾病预防控制中心（Center for Disease Control and Prevention，CDC）病毒病预防控制所国家脊灰实验室，对脊灰病毒阳性分离物的基因测序结果，各级CDC对VDPV及病例的调查和处置报告。结果2001～2013年，中国AFP病例监测系统从37名儿童粪便标本中分离到VDPV，来源于12个省，其中AFP病例22例，AFP病例接触者13人，健康儿童2人。其中2004年贵州省2例Ⅰ型（Type1）VDPV（VDPVI）病例形成循环（Circulating）（cVDPVⅠ），2011～2012年四川省Ⅱ型（Type2）疫苗高变异脊灰病毒（Vaccine—hypervariable Poliovirus，VHPVⅡ）病例／VDPVⅡ病例形成cVHPVⅡ／cVDPVⅡ。结论VDPV可在健康儿童粪便中检出，也能导致儿童麻痹。其发生有疫苗因素，也有受种者因素和疫苗使用因素。口服脊灰减毒活疫苗（Oral Poliomyelitis Attenuated Live Vaccine，OPV）接种率低，是造成发生cVDPV的原因。只有达到人群OPV的高免疫覆盖率，通过高质量的AFP病例监测系统及时发现病例，采取有效措施及时控制疫情，才能阻断病毒的传播。

The Epidemiology Characteristics Analysis of Vaccine-derived Poliovirus and Cases in China, 2001 -2013

Objective To evaluate the epidemiological characteristics of vaccine-derived polioviruses （VDPV） and cases from the Acute Flaccid Paralysis （AFP） Case Surveillance System in China, 2001 -2013. Methods The following data sources were analyzed： AFP reported from 31 provinces , VP1 sequencing results from the National Polio Laboratory, investigation reports, and emergency response reports from all levels of Centers for Disease Control and Prevention （CDC）. Results VDPVs were isolated from 37 children, including 22 AFP cases, 13 AFP contacts, and 2 healthy children from enterovirus surveillance among healthy children. The VDPVs were isolated from 12 provinces. Circulating type 1 VDPV （ cVDPVⅠ ） in Guizhou, 2004, and circulating vaeeine-hypervariable poliovirus/vaccinederived poliovirus 2 （cVHPVⅡ/cVDPVⅡ ） in Sichuan were found in the period from 2011 -2012. Conclusion VDPVs can be isolated from healthy children and can lead to paralysis. VDPVs were related to oral poliomyelitis attenuated live vaccine （OPV） coverage. Lower OPV coverage is the main cause of cVDVPs. High quality of the AFP case surveillance system for earlier VDPV detection, effective and successful OPV campaigns are important methods for interruption of virus transmission.