title: Nationwide distribution of varicella-zoster virus clades in China.
abstract: BACKGROUND
  In 2010, a universal nomenclature for varicella-zoster virus (VZV) clades was established, which is very useful in the monitoring of viral evolution, recombination, spread and genetic diversity. Currently, information about VZV clades has been disclosed worldwide, however, there are limited data regarding the characterization of circulating VZV clades in China, even where varicella remains widely epidemic.
  
  
  METHODS
  From 2008 to 2012, clinical samples with varicella or zoster were collected in General Hospital in eight provinces and analyzed by PCR, restriction endonuclease digestion and sequencing. The viral clades were determined by analysis of five single nucleotide polymorphisms (SNPs) within the 447-bp fragment of open reading frame (ORF) 22, and the restriction fragment length polymorphisms (RFLPs) of ORF 38 (PstI), ORF 54 (BglI) and ORF 62 (SmaI) were evaluated to understand genetic diversity of VZV and determinate varicella vaccine adverse event (VVAE).
  
  
  RESULTS
  Seventy-seven varicella and 11 zoster samples were identified as being positive for VZV. The five SNPs profile showed that the majority of VZV strains belonged to clade 2, but clade 5 and clade 4 strains were also found in Guangdong. The RFLPs analysis of the DNA fragments of ORF 38, 54 and 62 showed that 85 of these samples were characterized as PstI + BglI + SamI-, and the remaining three VZV strains from varicella patients were characterized as PstI-BglI + SamI+ which is the genetic profile of VVAEs.
  
  
  CONCLUSIONS
  The study suggested that the predominant clade 2 VZVs had been continually circulating since at least the 1950s in China. Nearly all VZV strains except VVAEs possessed the genetic profile of PstI + BglI + Sam-. However, the other clades were also found to be co-circulating with clade 2, especially in the border regions. These results highlighted the need for the constant and broad use of virologic surveillance to provide an important genetic baseline for varicella control and vaccination programs in China.
authors.affiliation: National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Beijing City, 102206, China.
authors.forename: Songtao
authors.initials: S
authors.lastname: Xu
authors.affiliation: The First Affiliated Hospital of Sun Yat-sen University, Guangzhou City, 510080, Guangdong Province, China.
authors.forename: Mukai
authors.initials: M
authors.lastname: Chen
authors.affiliation: Guangdong Center for Disease Control and Prevention, Guangzhou City, 510300, Guangdong Province, China.
authors.forename: Huanying
authors.initials: H
authors.lastname: Zheng
authors.affiliation: Shandong Center for Disease Control and Prevention, Jinan City, 250014, Shandong Province, China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Wang
authors.affiliation: Beijing Center for Disease Control and Prevention, Beijing City, 100021, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Chen
authors.affiliation: Jilin province Center for Disease Control and Prevention, Changchun City, 130021, Jilin Province, China.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Jilin province Center for Disease Control and Prevention, Changchun City, 130021, Jilin Province, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Shuang
authors.affiliation: Shaanxi Center for Disease Control and Prevention, Xian City, 710012, Shannxi Province, China.
authors.forename: Pengbo
authors.initials: P
authors.lastname: Yu
authors.affiliation: Xi'an city Center for Disease Control and Prevention, Xian City, 710031, Shannxi Province, China.
authors.forename: Chaofeng
authors.initials: C
authors.lastname: Ma
authors.affiliation: Sichuan Center for Disease Control and Prevention, Chengdu City, 610014, Sichuan Province, China.
authors.forename: Jilan
authors.initials: J
authors.lastname: He
authors.affiliation: Henan Center for Disease Control and Prevention, Zhengzhou City, 450016, Henan Province, China.
authors.forename: Daxing
authors.initials: D
authors.lastname: Feng
authors.affiliation: National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Beijing City, 102206, China.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Zhen
authors.affiliation: National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Beijing City, 102206, China.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Yan
authors.affiliation: National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Beijing City, 102206, China.
authors.forename: Mao
authors.initials: M
authors.lastname: Naiying
authors.affiliation: National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Beijing City, 102206, China.
authors.forename: Aili
authors.initials: A
authors.lastname: Cui
authors.affiliation: National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Beijing City, 102206, China.
authors.forename: Qiuhua
authors.initials: Q
authors.lastname: Wu
authors.affiliation: Department of Neurosurgery, Second Affiliated Hospital of Dalian Medical University, Dalian, 116027, Liaoning Province, China.
authors.forename: Mengyuan
authors.initials: M
authors.lastname: Qi
authors.affiliation: Shanghai Center for Disease Control and Prevention, Shanghai City, 200336, China. 94114911@qq.com.
authors.forename: Chongshan
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Neurosurgery, Second Affiliated Hospital of Dalian Medical University, Dalian, 116027, Liaoning Province, China. xuxg2007@sina.com.
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Xu
authors.affiliation: National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Beijing City, 102206, China. wenbo_xu1@aliyun.com.
authors.forename: Wenbo
authors.initials: W
authors.lastname: Xu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005075:Biological Evolution; D002644:Chickenpox / Q000453:epidemiology / Q000821:virology; D019433:Chickenpox Vaccine / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D005838:Genotype; D006562:Herpes Zoster / Q000453:epidemiology / Q000821:virology; D014645:Herpesvirus 3, Human / Q000235:genetics* / Q000302:isolation & purification; D006769:Hospitals, General; D006801:Humans; D008875:Middle Aged; D016366:Open Reading Frames; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D055815:Young Adult
chemical_list: D019433:Chickenpox Vaccine
keywords: China; Clade; Genetic profile; Varicella vaccine adverse event; Varicella-zoster virus