滨州市在急性弛缓性麻痹病例中发现疫苗衍生脊髓灰质炎病毒及其应急处置效果分析

Analysis on Vaccine-derived Poliovirus Found from Acute Flaccid Paralysis Cases and Effectiveness for Emergency Response in Binzhou in 2007

目的对山东省滨州市2007年发现的疫苗衍生脊髓灰质炎(脊灰)病毒(Vaccine-derived Poliovirus,VDPV)及其应急处置情况进行分析。方法运用现场流行病学爆发调查、快速评价与主动监测、病例管理、病毒学和血清学监测、应急免疫干预等方法进行综合处置,并对调查结果和应急处置效果进行综合分析评价。结果急性弛缓性麻痹(Acute Flaccid Paralysis,AFP)病例来自监测系统,临床诊断为格林巴利综合征,粪便标本检出Ⅰ型脊灰病毒,经核苷酸序列测定和分析鉴定为VDPV,曾接种过11剂口服脊灰减毒活疫苗(Oral Poliomyelitis Attenuated LiveVaccine,OPV),自身免疫功能基本正常。经调查,当地儿童OPV接种率和脊灰中和抗体水平均处较高水平,周围健康儿童粪便标本未分离到类似病毒,AFP病例监测系统灵敏有效,主动搜索未发现类似病例。对该病例连续采集粪便标本检测,未再发现VDPV。山东省AFP病例分类专家诊断小组诊断为VDPV感染者。结论此次发现的VDPV发生在OPV高免疫覆盖率地区,但未发现形成VDPV循环的证据,所采取的应急处置措施快速、有效。应进一步加强VDPV监测和产生原因及其传播链的研究。

Objective To analyze VDPV found from acute flaccid paralysis cases and effectiveness for emergency response in Binzhou,Shandong in 2007.Methods Outbreak investigation,rapid evaluation for oral poliomyelitis attenuate live vaccin（eOPV）coverage rate,active searched for acute flaccid paralysis （AFP）cases,supervision for VDPV case,virology and serology surveillance,mopping-up of OPV were used for this emergency response to prevent the possible VDPV spread.Results The case was reported from the AFP surveillance system.The poliovirus type I was isolated from stool specimen,which was identified as VDPV by gene sequencing.This AFP case was diagnosed as Guillain-barre syndrome（GBS） with 11 doses of OPV and normal self-immunity function test.The investigation results showed that the OPV coverage rates and the neutralization antibody to poliovirus type 1-3 were at high level among the local children,no similar VDPV was isolated from stools of healthy children around the case.The quality of AFP surveillance system was good,and had not found additional similar case in Bizhou city.Additional VDPV was not found in continuous stool specimen from this case.The case was diagnosed as VDPV infected vector but not VDPV case by the national and provincial expert group.Conclusion This VDPV was found in the area with high coverage rate OPV,There was no evidence for the VDPV circulation.The emergency response for the VDPV was rapid and effective.The VDPV surveillance and research related should be strengthened.