云南省边境地区输入性麻疹野病毒的分子流行病学监测

Molecular Epidemiological Surveillance of Imported Wild Measles Virus along the Borders of Yunnan Province

目的分析输入性麻疹野病毒对云南省边境地区麻疹分子流行病学的影响。方法用淋巴信号激活因子转染的非洲绿猴肾细胞(Vero/SLAM细胞),从麻疹患者的标本中分离麻疹病毒,用逆转录-聚合酶链反应(RT-PCR)扩增核蛋白(Nucleoprotein,N)基因羧基末端的676个核苷酸片段,对扩增产物进行核苷酸序列测定。并以N基因羧基末端450个核苷酸序列构建基因亲缘性关系树,进行核苷酸变异分析。结果云南省于2009年监测到麻疹病毒株MVi/Menglian.Yunnan.CHN/47.09/1,经过世界卫生组织(WHO)认定为D11基因型,为全球首次发现,并将此毒株定为D11基因型的标准株;云南省于2012年监测到麻疹病毒株MVi/Yunnan.CHN/02.12/01,在亲缘性关系树上与D9基因型参考株同在一个大的分支,同源性为96.3%,为D9基因型麻疹病毒。两起麻疹疫情均为输入性麻疹野病毒。结论两次输入性麻疹病毒均造成云南省边境地区的流行,云南省在含麻疹成分疫苗的常规免疫基础上适时进行强化免疫,有效阻断了输入麻疹病毒的传播。

Objective To analyze the molecular characteristics of imported measles virus in the border areas of Yunnan province. Methods We collected specimens from measles patients to isolate virus by using Vero / SLAM cells. Fragments of 676 nucleotide acids from the carboxyl end of nucleoprotein gene were amplified with reverse transcription-polymerase chain reaction（ RT-PCR） and the PCR products were directly sequenced and analyzed. A phylogenetic tree was constructed based on the 450 nucleotide acids of the carboxyl end of nucleoprotein gene; homological analysis was performed at both the nucleotide acid level and the amino acid level. Results MVi / Menglian. Yunnan. CHN /47. 09 /1 [D11 ],which was first isolated globally in 2009,was considered to be a member of a newly proposed measles genotype and chosen as a reference strain by the World Health Organization（ WHO）. The Yunnan isolates of MVi / Yunnan. CHN /02. 12 /01[D9] isolated in 2012 clustered within the same genotype as the WHO D9 genotype reference stain. The homology of nucleotide acids between the Yunnan isolates and the WHO reference strains was 96. 3%. Genotypes D11 and D9 were detected from imported measles cases.Conclusions Imported measles viruses（ D11 and D9） caused measles epidemics in the border areas.With great effort to strengthen routine immunization and conduct timely supplementary immunization activities（ SIAs）,spread of imported measles virus was successfully interrupted.