2017年北京地区水痘病原学监测结果分析

Analysis on etiological surveillance results of varicella in Beijing, 2017

目的了解北京地区水痘–带状疱疹病毒(VZV)毒株类型及优势流行亚型,为水痘暴发疫情的防治提供依据。方法收集2017年北京地区水痘暴发疫情病例的疱疹液标本。采用实时荧光PCR方法,进行VZV及野毒株和疫苗株鉴定,根据VZV第22个开放阅读框基因片段序列,确定北京地区VZV进化关系。结果 2017年共收集到水痘病例标本316份,VZV病毒核酸阳性271份,阳性率为85.76%,均为野毒株。共获得240份VZV基因片段,其中234株毒株是clade2型,占97.50%,3株clade1型和3株clade4型,分别占1.25%。其中clade2型分布在北京地区16个区(县),clade1型和clade4型分别分布在西城区和大兴区。结论 2017年北京地区水痘病例主要由clade2型VZV引起,同时对新出现的clade1型和clade4型要加强监测。

Objective To understand the types and predominant types of varicella-zoster virus(VZV) in Beijing,2017,and provide evidence for the prevention and control of varicella.Methods The clinical vesicular fluid was collected from the varicella cases detected in outbreak of Beijing in 2017 for the identification of wild strains and vaccine strains of VZV with real-time PCR.The phylogenetic analysis on wild VZV in Beijing was performed based on the sequences of twenty-second open reading frame gene fragment(ORF).Results Among the 316 vesicular fluid specimens from varicella cases,271 were positive for VZV.All of these strains belonged to wild VZV strains.The gene fragments were obtained for 240 of 271 wild strains.They belonged to 3 serotypes,including 234 clade 2 strains(97.50%),3 clade 1 strains(1.25%) and 3 clade 4 strains(1.25%).Clade 2 strains was distributed in all of 16 districts of Beijing,and clade 1 and clade 4 strains were distributed in Xicheng and Daxing districts,respectively.Conclusion The varicella cases were mainly caused by clade 2 VZV in Beijing in2017.It is necessary to strengthen the surveillance for new clade 1 and clade 4 VZV.