title: Molecular epidemiology of enterovirus 71 infection in the Western Pacific Region.
abstract: BACKGROUND
  Recently, there have been large outbreaks of hand, foot and mouth disease (HFMD) mainly caused by enterovirus 71 (EV71) associated with severe neurological diseases in the Western Pacific Region (WPR). To monitor the realtime trend of EV71 transmission throughout the WPR, the authors conducted a molecular epidemiological analysis of EV71 infection.
  
  
  METHODS
  Viruses were isolated from clinical samples from patients with HFMD or those with neurological complications. The EV71 isolates were identified by microneutralization assay. The VP4 and/or VP1 regions of recent EV71 isolates were sequenced and subjected to phylogenetic analysis using reference EV71 strains.
  
  
  RESULTS
  The phylogenetic analysis of EV71 isolates from the WPR revealed two major genogroups, B and C, based on the nucleotide sequence alignment of the VP1 or VP4 region. These two major genogroups were further divided into subgenogroups, B1, B2, B3, and B4 and C1, C2, C3 and C4, respectively.
  
  
  CONCLUSIONS
  The molecular epidemiological analyses of recent and previous EV71 isolates in the WPR indicated that two major genogroups of EV71 are co-circulating in Australia, Malaysia, Singapore, Taiwan and Japan. Recent EV71 isolates in Mainland China constitute a new distinct genetic cluster, subgenogroup C4. Two major lineages of EV71 are the major causative agents of the present HFMD epidemics in the WPR and both are considered to be neurovirulent.
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan. hshimizu@nih.go.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Shimizu
authors.forename: Andi
authors.initials: A
authors.lastname: Utama
authors.forename: Napa
authors.initials: N
authors.lastname: Onnimala
authors.forename: Chen
authors.initials: C
authors.lastname: Li
authors.forename: Zhang
authors.initials: Z
authors.lastname: Li-Bi
authors.forename: Ma
authors.initials: M
authors.lastname: Yu-Jie
authors.forename: Yaowapa
authors.initials: Y
authors.lastname: Pongsuwanna
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Miyamura
mesh_terms: D002681:China / Q000453:epidemiology; D004770:Enterovirus / Q000235:genetics*; D006232:Hand, Foot and Mouth Disease / Q000453:epidemiology* / Q000821:virology; D006801:Humans; D013785:Thailand / Q000453:epidemiology