2005年山东省流动人口成人麻疹暴发的病毒基因特征分析

[目的]确定麻疹病毒株的来源、传播途径及变异情况，探讨流动人口和成人麻疹发病的特点。[方法]2005年在山东省邹平县麻疹暴发疫区采集病人血清和咽拭子标本，进行血清学、病原学和分子流行病学特征检测。[结果]从6例病人咽拭子标本分离4个病毒流行株．均为H1基因型．3株属于H1a．1株属于H1b。4株之间核苷酸、氨基酸同源性为95．80％～100．00％、97．30％～100．00％，分成2个亚支、2个亚型，与H2基因型参考株中国疫苗株S191之间存在较大的遗传差异（8．60％）．与山东省2005年另外7株病毒株的基因型别分布相似。3株H1a病毒株又分为2个小分支．1株与2005年另外2株H1b病毒株（枣庄市、泰安市）的亲缘关系最近，与2000年的3株H1b病毒株（淄博市）亲缘关系较远．不属于同一祖先传播链病毒株。[结论]2005年邹平县成人麻疹暴发是由H1a、H1b两个亚型病毒株引起．以本地流行优势基因亚型H1a为主，H1b亚型为外来输入并在山东省少数市地传播。

Stduy on Genetic Characterization of Wild-type Measles Viruses in Measles Outbreak in Adult Floating Population in Shandong Province in 2005

[Objective]To study the causes and the variance of wild-type measles viruses and find out the character of measles viruses among the adults. [Methods]Serum and throat swab samples were collected from the patients in measles outbreak area in Zouping county of Shandong province in 2005 ,and the characters on serology,etiology and molecular epidemiology were analyzed. [Results]The 4 epidemic viral strains isolated from throat swab samples from six measles patients were all H1 genotype, three strains of the four belonged to Hla sub-genotype of H1 genotype,and the other one belonged to Hlb sub-genotype of H1 genotype. The homology of nucleotide acid sequence and amino acid sequence among the four strains were 95.80% to 100. 00%, 97.30% to 100. 00%;the variation of them were 8.60% compared with the S191 genotype;the genotype distribution of the four strains were similar to other seven strains isolated in Shandong prov- ince in 2005. There were two small clusters within the three Hla sub-genotype strains. This Hlb sub-genotype strain was similar to the two strains isolated from Zaozhuang and Tai＇an in 2005 ,but was different with thc three strains isolated from Zibo in 2000. [Conclusion]This was an outbreak of measles among adults caused by Hla sub-gcnotype and Hlb sub-genotype. Hla sub-genotype was the major genotype of wild type meals viruses circulated in Shandong,and Hlb sub-genotype was exotic-imported genotype circulated in few cities.