中国2012年脊髓灰质炎实验室网络的运转与评价

目的通过对中国2012年脊髓灰质炎（脊灰）实验室网络（Polio Laboratory Network，PLN）监测数据（未包括香港、澳门特别行政区和台湾地区，下同）进行统计分析，评估其运转情况，为中国重新恢复无脊灰状态提供实验室依据。方法分析中国免疫规划监测信息管理系统数据库中，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）病例个案调查表和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（National Polio Laboratory，NPL）的监测数据库，总结PLN运转中的质量控制，评价PLN的各项运转指标。结果中国2012年PLN共收集了6163例AFP病例的12204份粪便标本，14d内双份粪便标本采集率为92．6％，合格粪便标本采集率为92．1％。按世界卫生组织（World Health Organization，WHO）第4版《脊灰实验室手册》的要求进行病毒分离和鉴定，试验结果28d内及时反馈率为99％。2012年，在116例AFP病例粪便标本中分离到脊灰病毒（Poliovirus，PV），分离率为2．10％（116／5534）；在680例AFP病例粪便标本中分离到非脊灰肠道病毒（Non—polio Enterovirus，NPEV），分离率为12．29％（680／5534）。2012年，NPL收到PLN送检的283株PV，对375株单血清型PV采用衣壳蛋白（Capsid Protein）VP1编码区核苷酸序列测定与分析进行型内鉴定（Intratypic Differentiation，ITD），发现7例（共计25株）疫苗衍生（Vaccine—derived）PV（VDPV），其中Ⅰ型2株，Ⅱ型16株，Ⅲ型7株，未发现野生型（Wild Type）PV（WPV）。2012年，NPL收到环境监测送检的314株PV，全部采用VP1编码区核苷酸序列测定与分析进行ITD，在山东省发现1株VDPV。2012年8月，NPL作为WHO西太平洋区脊灰参比实验室接受并以优异的成绩通过了WHO的年度现场认证；2012年10月，NPL以满分的成绩通过了荧光定量聚合酶链反应（Polymerase Chain Reaction，PCR）和VDPV筛查的职能考核；2012年12月，又以满分通过了WHO核苷酸序列测定和分析的第一次职能考核。在中国PLN中，有11个省级CDC脊灰实验室参加并通过了WHO的实验室现场评估认证；22个省级CDC脊灰实验室参加并以满分的成绩通过了荧光定量PCR和VDPV筛查的职能考核。2012年10月9日，WHO通过对中国AFP病例监测质量和结果的评估，宣布中国重新恢复无脊灰状态。结论2012年，PLN运转正常、敏感有效，在AFP病例和环境监测中未发现WPV，为中国恢复无脊灰状态提供了关键的技术支撑作用。

The Running Status and Evaluation of the Chinese Polio Laboratory Network in 2012

Objective To analyze 2012 data from the polio laboratory network （PLN; excluding Hong Kong Special Administrative Region, Macao Special Administrative Region, and Taiwan Sheng）, to evaluate the running status of the network, and to provide lab evidence that China is polio-free. Methods Evaluated Acute Flaccid Paralysis （AFP） case investigation reports from the Expanded Program on Immunization Surveillance Information Management System in 31 provinces （ municipalities, autonomous regions）, and the surveillance data from the National Polio Laboratory （NPL）. The qualitative controls and evaluate indicators of PLN running status were summarized. Results A total of 12,204 stool samples were collected from 6,163 AFP cases by the Chinese PLN in 2012. The double-stool sample collection rate was 92.6% and the rate of adequate stool sample collection was 92. 1%. All stool samples used for virus isolation and identification, in accordance with the 4th edition World Health Organization（WHO） Polio Laboratory Manual. The rate of virus isolation and identification performed within 28 days was 99.0%. Polioviruses （PV） were isolated from 116 AFP cases at a rate of 2.1% （116/5534）, and non-polio enteroviruses （NPEV） were isolated from 680 AFP cases at a rate of 12.29% （680/5534）. A total of 283 PV strains were sent to the NPL from PLN. Caspid protein VP1 encoding region sequencing and intratypic differentiation （ITD） were performed for 375 single serotype PVs strains in 2012. No wild PVs were found, and 7 vaccine-derived polioviruses （VDPVs） cases （25 strains） were identified. Three hundred and fourteen single serotype PVs strains were sequenced among the viral isolates from environmental surveillance, and 1 VDPV was found in Shandong. The NPL passed the test of real-time polymerase chain reaction （PCR） intratypic differentiation （ITD） and VDPV screening and VP1 sequencing with full scores, and also got received accreditation following on-site review by WHO experts in 2012. Eleven provincial polio laboratories also joined and passed the on-site review by WHO experts. Twenty-two provincial polio laboratories joined and passed real-time PCR ITD and VDPV screening with full scores. On 9th Oct, 2012, WHO declared that China had regained the ＂polio-free status＂ according to the evaluation of the quality and the AFP surveillance results. Conclusion The running status of Chinese PLN in 2012 was in good condition; the laboratory surveillance system was sensitive; and no wild PVs were found in AFP cases surveillance and environmental surveillance. The laboratory played a key role in maintaining polio-free status in China.