陕西省脊髓灰质炎病毒检测分析

Detection of acute flaccid paralysis (AFP) cases and poliovirus in Shaanxi province

目的分析陕西省2003-2008年检出脊髓灰质炎(以下简称脊灰)病毒(PV)的急性弛缓性麻痹(AFP)病例流行病学特征,提高对疫苗衍生脊灰病毒(VDPV)监测的敏感性。方法对PV阳性的AFP病例相关资料进行流行病学分析,对疫苗变异PV采用VP1基因核苷酸序列测定方法进行分子生物学性状分析。结果陕西省2003-2008年共检出PV 29株,分离到的PV以Ⅱ型为主(15株),超过Ⅰ型和Ⅲ型之和;AFP病例集中在≤2岁儿童(75.86%),以零剂次免疫和未全程免疫儿童所占比例较大(51.72%);麻痹部位主要为单下肢、双下肢和四肢;型内鉴定14株为疫苗变异PV,基因序列测定均未达到VDPV(1%)的诊断标准;疫苗变异PV的病例中7例为未全程免疫,9例为0～2岁儿童。结论维持无脊灰阶段,存在着VDPV和发生循环疫苗衍生脊灰病毒(cVDPVs)爆发流行的可能,保持高水平的脊灰减毒活疫苗(OPV)免疫覆盖率,高质量的AFP病例流行病学监测和病毒学监测,具有重要现实意义。

Objective To analyze the epidemiological character of AFP cases and to detect poliovirus in Shaanxi province during 2003-2008 in order to increase the sensitivity of vaccine-derived poliovirus（VDPVs） surveillance.Methods Epidemiological analysis was conducted in AFP cases with positive poliovirus detection and VP1 genomic sequencing technique was used to analyze the molecular character of vaccine-variant polioviruses.Results From 2003 to 2008,29 poliovirus strains were isolated from AFP cases,and the number of type Ⅱ strains exceed to the summation of type Ⅰ and type Ⅲ strains.75.86% of cases were children.The main paralysis parts of body were single or both lower extremity and limbs.Fourteen strains were indentified as vaccine-variant poliovirus.The variant rate of VP1 sequence did not reach 1%.Among these cases,7 cases were not fully vaccinated children and 9 were under 2 years old.Conclusion VDPV emergence and cVDPVs circulation still possibly occur in course of polio-eradication.It is important to keep high-level surveillance and vaccination coverage.