2017—2018年湖南省急性弛缓性麻痹病例病原学监测分析

目的 分析2017—2018年湖南省脊灰实验室所用细胞系的滴度值、急性弛缓性麻痹(acute flaccid paralysis,AFP)病例病原学特征、非脊髓灰质炎肠道病毒(non-polio enterovirus,NPEV)分离率及分布情况,为维持无脊灰状态及预防其传播提供依据。 方法 依照WHO《脊髓灰质炎病毒检验手册》(2004年第四版)方法,对AFP病例粪便标本采用鼠肺细胞(mouse L cells expressing the human poliovirus receptor, L20B)和人横纹肌肉瘤细胞(rhabdomyosarcoma, RD)进行肠道病毒(enterovirus, EV)分离,L20B细胞阳性分离物转RD细胞阳性者再进行脊髓灰质炎型内鉴定实验,脊髓灰质炎阳性毒株送中国疾病预防控制中心国家脊髓灰质炎实验室进行型内鉴定。 结果 在506例(1 011份)AFP病例标本中,分离出脊髓灰质炎病毒(polioviru,PV)2株、NPEV 77株,分离率分别为0.20％、7.62％;2株I型PV阳性毒株均有2个核苷酸序列变异,未发现脊髓灰质炎野病毒和疫苗衍生脊灰病毒,0～1岁组AFP病例NPEV分离率最高。 结论 2017—2018年湖南省脊灰实验室所用细胞系对脊灰病毒的敏感性良好,未发现脊灰野病毒,继续维持了无脊灰状态。

Virological surveillance of acute flaccid paralysis cases in Hunan province,2017-2018

Objective To analyze the titer values of cell lines used in Hunan Provincial Polio Laboratory during 2017-2018,etiological characteristics of acute flaccid paralysis(AFP)cases,and isolation rate and distribution of non-polio enterovirus(NPEV),and to provide a basis for maintaining polio-free state and preventing its transmission.Methods In accordance with the method of Polio Laboratory Manual(4 th edition,2004)recommended by World Health Organization,mouse L cells expressing the human poliovirus receptor(L20 B)and rhabdomyosarcoma(RD)cells were cultured for isolation of enteroviruses(EV)in the stool specimens of AFP cases.L20 B-positive isolates were inoculated into RD cells again,and then intratypic differentiation(ITD)of poliovirus isolates and vaccine-derived poliovirus(VDPV)detection were conducted.Polio-positive strains were sent to the National Polio Laboratory in Chinese Center for Disease Control and Prevention for intratypic identification.Results Two strains of poliovirus(PV)and 77 strains of non-poliomyelitis enterovirus(NPEV)were isolated from 1,021 specimens of 506 AFP cases,with the isolation rates being 0.20%and 7.62%,respectively.Two site-specific nucleotide sequence variations were found in two strains of PV type I,but no polio wild strain and VDPV were observed.The isolation rate of NPEV was discovered to be the highest in the AFP cases aged 0-1 year.Conclusions The cell lines used in Hunan Provincial Polio Laboratory during 2017-2018 showed a good sensitivity to poliovirus.No wild poliovirus was detected,and polio-free status was maintained.