中国境内首次发现输入性D4基因型麻疹病例

The First Imported Measles Case Associated with Genotype D4 Measles Virus in China

本文报道了2009年中国首例输入性D4基因型麻疹病例。使用Vero/SLAM细胞(淋巴信号激活因子转染的非洲绿猴肾细胞)对该麻疹病例的咽拭子标本进行麻疹病毒分离,经逆转录聚合酶链反应(Reverse transcript polymerase chain reaction,RT-PCR)方法扩增出麻疹病毒核蛋白(Nucleoprotein,N)羧基(COOH)端676个核苷酸片段。通过对扩增产物进行核苷酸序列测定和分析,以COOH端450个核苷酸片段构建基因亲缘性关系树,进行核苷酸和氨基酸同源性分析。该麻疹病毒分离株(MVi/Shanxi.CHN/20.09/1)和WHOD4基因型参考株Mont-real.CAN/89在基因亲缘性关系树上同属一个分支,核苷酸同源性为97.3%;与2009年流行于美国、加拿大、印度和俄罗斯的D4基因型麻疹野病毒的核苷酸和氨基酸同源性分别为98.0%～100%和97.3%～100%。结果表明,在本次输入性麻疹病例中分离到的麻疹病毒属于D4基因型,这对积累我国麻疹分子流行病学基线数据具有很重要的意义,同时也有助于监测和阐明麻疹病毒的传播途径。

This study reported the first imported measles case associated with genotype D4 measles virus in Shanxi province in China. The clinical specimen of throat swab was inoculated into Vero/SLAM culture to isolate the virus. A RT-PCR（Reverse transcription polymerase chain reaction,RT-PCR）was performed to amplify the 676 nucleotides sequence corresponding to the carboxyl terminus of measles virus nucleoprotein. The phylogenetic tree based on the 450 nucleotide acids of carboxyl terminus of N protein was constructed and the homology similarity was analyzed. The Shanxi isolate MVi/Shanxi.CHN/20.09/1 was clustered within the same genotype group with WHO genotype D4 reference strain,Montreal.CAN/89,and the homology of nucleotide acid between Shanxi isolate and WHO genotype D4 reference strain was 97.3%. The homology of nucleotide acid and amino acid between Shanxi isolate and 2009 genotype D4 representative strain circulating in USA,Canada,India and Russian were 98.0%-100% and 97.3%-100%,respectively. These results showed that the virus isolated from the imported measles case was genotype D4. This is the first report that the genotype D4 measles virus was imported and isolated in China. It is important to accumulate baseline data of China and help to measure transmission pathways and to clarify epidemiological links.