水痘暴发疫情中突破性病例病毒基因特征研究

Genetic characteristics of breakthrough varicella-zoster virus infection during the varicella outbreaks in Minhang District of Shanghai

目的：分析明确上海市闵行区2013—2014年水痘突破性病例致病水痘-带状疱疹病毒流行株的基因特征。方法采集闵行区2013—2014年水痘暴发点水痘罹患者水痘疱疹液,提取水痘病毒基因组DNA,对其ORF22和ORF62区域进行测序,并利用生物信息学方法对ORF22和ORF62序列特征进行分析。结果上海市闵行区2013—2014年水痘暴发疫情中采集并测序成功的24份样本经分析表明均为野生型水痘病毒株,其中23株与亲本株（ P-Oka）和疫苗株（ V-Oka）同源性较高,推测为野生型J基因水痘病毒株,1株基因型介于M型和E型间,与mosaic（M）CA123株（M1）同源性更高,推测其可能为野生型M1基因水痘病毒株。结论上海市闵行区流行的水痘病毒株主要为野生型J基因病毒株,也有M基因型和其他基因型局部流行。同为J基因型的不同野生型病毒株的基因间也存在一定变异。这些非疫苗保护基因型水痘病毒株的存在及流行可能是水痘突破病例产生的原因之一。

Objective To analyze the genetic characteristics of breakthrough varicella-zoster virus infection during the varicella outbreaks in Minhang District of Shanghai in 2013-2014. Methods Samples of the varicella-zoster liquid were collected from patients with chickenpox in Minhang District in 2013-2014 and used for the extraction of genomic DNA. The open reading frame （ ORF） of 22 and 62 regions were se-quenced and further analyzed by using bioinformatics methods. Results A total of 24 samples were success-fully collected and sequenced, and all of them were wild strains. Among the 24 varicella-zoster virus strains, 23 strains were highly homologous to the parental strain （ P-Oka） and the vaccine strain （ V-Oka） , indica-ting that they belonged to J genotype. Only one strain, whose genotype was between M and E, was highly ho-mologous to the mosaic（ M） CA123 strain （ M1 genotype） , indicating that it might belong to M1 genotype. Conclusion The epidemic strains of varicella-zoster virus in Minhang District were mainly J genotype. Lo-cal epidemic of M and other genotypes of varicella-zoster virus also existed. There were some gene variations in different strains of J genotype. These varicella-zoster virus strains of non-vaccine genotypes might be one of the reasons causing the breakthrough cases of chicken pox.