title: Single endemic genotype of measles virus continuously circulating in China for at least 16 years.
abstract: The incidence of measles in China from 1991 to 2008 was reviewed, and the nucleotide sequences from 1507 measles viruses (MeV) isolated during 1993 to 2008 were phylogenetically analyzed. The results showed that measles epidemics peaked approximately every 3 to 5 years with the range of measles cases detected between 56,850 and 140,048 per year. The Chinese MeV strains represented three genotypes; 1501 H1, 1 H2 and 5 A. Genotype H1 was the predominant genotype throughout China continuously circulating for at least 16 years. Genotype H1 sequences could be divided into two distinct clusters, H1a and H1b. A 4.2% average nucleotide divergence was found between the H1a and H1b clusters, and the nucleotide sequence and predicted amino acid homologies of H1a viruses were 92.3%-100% and 84.7%-100%, H1b were 97.1%-100% and 95.3%-100%, respectively. Viruses from both clusters were distributed throughout China with no apparent geographic restriction and multiple co-circulating lineages were present in many provinces. Cluster H1a and H1b viruses were co-circulating during 1993 to 2005, while no H1b viruses were detected after 2005 and the transmission of that cluster has presumably been interrupted. Analysis of the nucleotide and predicted amino acid changes in the N proteins of H1a and H1b viruses showed no evidence of selective pressure. This study investigated the genotype and cluster distribution of MeV in China over a 16-year period to establish a genetic baseline before MeV elimination in Western Pacific Region (WPR). Continuous and extensive MeV surveillance and the ability to quickly identify imported cases of measles will become more critical as measles elimination goals are achieved in China in the near future. This is the first report that a single endemic genotype of measles virus has been found to be continuously circulating in one country for at least 16 years.
authors.affiliation: WHO WPRO Regional Reference Measles Lab, National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, Beijing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Songtao
authors.initials: S
authors.lastname: Xu
authors.forename: Huiling
authors.initials: H
authors.lastname: Wang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhu
authors.forename: Yixin
authors.initials: Y
authors.lastname: Ji
authors.forename: Chunyu
authors.initials: C
authors.lastname: Liu
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Zhang
authors.forename: Liwei
authors.initials: L
authors.lastname: Sun
authors.forename: Jianhui
authors.initials: J
authors.lastname: Zhou
authors.forename: Peishan
authors.initials: P
authors.lastname: Lu
authors.forename: Ying
authors.initials: Y
authors.lastname: Hu
authors.forename: Daxing
authors.initials: D
authors.lastname: Feng
authors.forename: Zhenying
authors.initials: Z
authors.lastname: Zhang
authors.forename: Changyin
authors.initials: C
authors.lastname: Wang
authors.forename: Xueqiang
authors.initials: X
authors.lastname: Fang
authors.forename: Huanying
authors.initials: H
authors.lastname: Zheng
authors.forename: Leng
authors.initials: L
authors.lastname: Liu
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Sun
authors.forename: Wei
authors.initials: W
authors.lastname: Tang
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Hui
authors.initials: H
authors.lastname: Gao
authors.forename: Hong
authors.initials: H
authors.lastname: Tian
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Ma
authors.forename: Suyi
authors.initials: S
authors.lastname: Gu
authors.forename: Shuang
authors.initials: S
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Feng
authors.forename: Fang
authors.initials: F
authors.lastname: Bo
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Liu
authors.forename: Yuan
authors.initials: Y
authors.lastname: Si
authors.forename: Shujie
authors.initials: S
authors.lastname: Zhou
authors.forename: Yuyan
authors.initials: Y
authors.lastname: Ma
authors.forename: Shengwei
authors.initials: S
authors.lastname: Wu
authors.forename: Shunde
authors.initials: S
authors.lastname: Zhou
authors.forename: Fangcai
authors.initials: F
authors.lastname: Li
authors.forename: Zhengrong
authors.initials: Z
authors.lastname: Ding
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Yang
authors.forename: Paul A
authors.initials: PA
authors.lastname: Rota
authors.forename: David
authors.initials: D
authors.lastname: Featherstone
authors.forename: Youngmee
authors.initials: Y
authors.lastname: Jee
authors.forename: William J
authors.initials: WJ
authors.lastname: Bellini
authors.forename: Wenbo
authors.initials: W
authors.lastname: Xu
mesh_terms: D002681:China / Q000453:epidemiology; D005814:Genes, Viral / Q000235:genetics*; D005838:Genotype; D006801:Humans; D015994:Incidence; D008457:Measles / Q000453:epidemiology / Q000635:transmission* / Q000821:virology; D008459:Measles virus / Q000235:genetics* / Q000302:isolation & purification; D011159:Population Surveillance