title: The persistent circulation of enterovirus 71 in People's Republic of China: causing emerging nationwide epidemics since 2008.
abstract: Emerging epidemics of hand-foot-and-mouth disease (HFMD) associated with enterovirus 71 (EV71) has become a serious concern in mainland China. It caused 126 and 353 fatalities in 2008 and 2009, respectively. The epidemiologic and pathogenic data of the outbreak collected from national laboratory network and notifiable disease surveillance system. To understand the virological evolution of this emerging outbreak, 326 VP1 gene sequences of EV71 detected in China from 1987 to 2009 were collected for genetic analyses. Evidence from both traditional and molecular epidemiology confirmed that the recent HFMD outbreak was an emerging one caused by EV71 of subgenotype C4. This emerging HFMD outbreak is associated with EV71 of subgenotype C4, circulating persistently in mainland China since 1998, but not attributed to the importation of new genotype. Originating from 1992, subgenotype C4 has been the predominant genotype since 1998 in mainland China, with an evolutionary rate of 4.6∼4.8×10⁻³ nucleotide substitutions/site/year. The phylogenetic analysis revealed that the majority of the virus during this epidemic was the most recent descendant of subgenotype C4 (clade C4a). It suggests that the evolution might be one of the potential reasons for this native virus to cause the emerging outbreak in China. However, strong negative selective pressure on VP1 protein of EV71 suggested that immune escape might not be the evolving strategy of EV71, predicting a light future for vaccine development. Nonetheless, long-term antigenic and genetic surveillance is still necessary for further understanding.
authors: National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
authors: Xiaojuan
authors: X
authors: Tan
authors: Xueyong
authors: X
authors: Huang
authors: Shuangli
authors: S
authors: Zhu
authors: Hui
authors: H
authors: Chen
authors: Qiuli
authors: Q
authors: Yu
authors: Haiyan
authors: H
authors: Wang
authors: Xixiang
authors: X
authors: Huo
authors: Jianhui
authors: J
authors: Zhou
authors: Yan
authors: Y
authors: Wu
authors: Dongmei
authors: D
authors: Yan
authors: Yong
authors: Y
authors: Zhang
authors: Dongyan
authors: D
authors: Wang
authors: Aili
authors: A
authors: Cui
authors: Hongqiu
authors: H
authors: An
authors: Wenbo
authors: W
authors: Xu
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D002681:China / Q000453:epidemiology; D002522:Chlorocebus aethiops; D004196:Disease Outbreaks; D029821:Enterovirus A, Human / Q000235:genetics / Q000472:pathogenicity*; D004769:Enterovirus Infections / Q000453:epidemiology* / Q000821:virology*; D019143:Evolution, Molecular; D005838:Genotype; D006801:Humans; D017720:Molecular Epidemiology; D010802:Phylogeny; D012641:Selection, Genetic; D014709:Vero Cells