2000年东莞市麻疹病毒流行株基因型分析

目的 了解东莞市麻疹病毒（measles virus,MV)流行株的基因型。方法 2000年4-7月间东莞市发生有55例患者的麻疹流行，采用逆转录-聚合酶链反应（RT-PCR）方法直接检测麻疹病人急性期唾液中的麻疹病毒核糖核酸（RNA）的N基因和M基因，对任意选取的5份RT-PCR阳性标本和疫苗株沪-191的N基因扩增片段进行核酸序列测定，并进行序列系统树分析。结果 用RT-PCR方法直接检测的阳性率为87.3%；用血清抗-MV-IgM ELISA方法检测的阳性率为70.9%，抗MV-IgM阴性的病人唾液中有68.8%的标本MV-RNA阳性。序列分析结果表明此流行株的基因型与世界麻疹病毒流行株不同，差异为1.4%-11.7%，可归属于H基因型。结论 2000年东莞市麻疹病毒流行核酸序列完全相同，为H基因型，说明本次流行的麻疹病毒具有同源性，来源于同一传染源。

Analysis on the genotype of measles virus epidemic strains in Don~uan city, Guangdong province in 2000

OBJECTIVE: To analyze the genotype of the measles virus epidemic strains in Dongguan according to the patients suffered measles in 2000. METHODS: The saliva of 55 patients with acute measles symptoms were collected and detected with RT-PCR. The PCR products of the 5 samples were sequenced and analyzed with the software DNASTAR. RESULTS: The positive detection rate was 87.3%, whereas the positive rate of anti MV-IgM in serum was only 70.9%. 68.8% of the saliva samples of patients with anti MV-IgM negative results showing MV RNA positive. The 293 bp fragment of N gene and 194 bp fragment of M gene were amplified from the vaccine virus and the specimens. The sequences of the epidemic strains were identical in both M gene and N gene. CONCLUSION: These results suggested that the outbreak came from a single MV strain. The epidemic strain was obviously different from the standard strains discovered in other countries of the world (the deviation were 1.4%-11.7%) that might belong to H genotype.