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1 997～ 2 0 0 1年 ,湖南省疾病预防控制中心从急性弛缓性麻痹 (AFP)病例粪便标本中共分离到单型脊髓灰质炎(脊灰 )毒株 85株 ,经中国疾病预防控制中心病毒病预防控制所国家脊灰实验室用逆转录 聚合酶链反应 限制性酶切片长度多态性分析 (RT PCR RFLP)方法进行型内鉴定 ,全部为疫苗相关株。对其中从“零”剂次免疫患儿、有残留麻痹患儿和一些其他相关的患儿粪便标本中分离到的脊灰病毒进行了VP1区和 3D区的核苷酸序列测定。结果显示 :在脊灰Ⅱ型毒株中 ,绝大多数毒株在VP1区的核苷酸中第 2 90 9位位点发生突变 ,导致第 1 4 3位氨基酸由Ile变为Asn或Thr。在脊灰Ⅱ型毒株中 ,广泛存在着型间重组现象。在重组病毒中 ,以Ⅱ型与Ⅲ型病毒的重组为主 ,占 90 %。从AFP病例及健康儿童中 ,从有残留麻痹患儿及无残留麻痹患儿的粪便标本中 ,都能分离到重组株 ,说明重组的发生具有普遍性 ,重组发生的位点在核苷酸的不同位置 ,重组的形式又具有多样性。通过对湖南省毒株的碱基突变和重组的研究表明 ,在湖南省 1 997～ 2 0 0 1年的分离株不支持隔年传播 ,只在局部地区某一年内可能发生有限的循环。通过加强口服脊灰疫苗的免疫 ,提高免疫覆盖率 ,可以阻止疫苗相关病毒局限的循环。
From 1997 to 2001, 85 cases of monomorphic poliomyelitis (polio) strains were isolated from the stool specimens of acute flaccid paralysis (AFP) in Hunan Provincial Center for Disease Control and Prevention. The Chinese Center for Disease Control and Prevention The National Institute of Disease Control and Prevention, the National Institute of Polymorphisms, was identified by the RT PCR RFLP method, all of which were vaccine-associated strains. The nucleotide sequences of VP1 region and 3D region of poliovirus isolated from stool samples from children with “zero” immunization, children with residual paralysis and some other related children were tested. The results showed that most of the strains of poliovirus type Ⅱ were mutated at the site of 9090 in VP1, resulting in the change of 143rd amino acid from Ile to Asn or Thr. In poliovirus type Ⅱ, there is widespread interspecies recombination. In the recombinant virus, the type II and type III virus recombination, accounting for 90%. From AFP cases and healthy children, from patients with residual paralysis and no residual paralysis in children with stool specimens, can be isolated from the recombinant strains, indicating that the occurrence of recombination is universal, the site of recombination occurred in the nucleotide Different locations, the form of reorganization and diversity. The study of base mutation and recombination in Hunan Province showed that isolates from 1997 to 2001 in Hunan province did not support annual transmission, and only a limited cycle could occur in some areas in a year. By strengthening the immunization of oral poliovirus vaccine to improve immune coverage, can prevent the cycle of vaccine-associated virus limitations.