title: Seroprevalence of Enterovirus 71 Antibody Among Children in China: A Systematic Review and Meta-analysis.
abstract: BACKGROUND
  Hand, foot and mouth disease mostly affects children and carries a substantial disease burden in the Western Pacific region. Enterovirus 71 (EV71) is the most virulent causative agent, and a monovalent vaccine against EV71 will soon become commercially available in China. An improved understanding of EV71 epidemiology would aid policy decisions regarding childhood immunization in China. We aimed to assess and summarize information to date from individual seroepidemiologic studies of EV71 in mainland China to determine patterns of the age-specific risk of infection.
  
  
  METHODS
  A systematic review and meta-analysis of studies of children aged 0-15 years, published in English or Chinese, was conducted. Estimates of seroprevalence were summarized by age group. A mixed-effects regression model was used to explore factors covarying with EV71 seroprevalence.
  
  
  RESULTS
  We identified 42 published studies, 15 in English. We found that an average of 78% of neonates was seropositive to EV71 infection, but such maternally conferred immunity almost completely waned by 5 months. The seroprevalence of EV71 antibody increased directly with age among preschool children, from 26% (95% confidence interval: 18%-33%) at 1 year to 70% (95% confidence interval: 62%-78%) at 5 years. Age of subjects, sample size, sampling year, sampling method, geographic latitude and publication language were associated with variations of individual seroprevalence estimates.
  
  
  CONCLUSIONS
  Seroprevalence of EV71 antibody gradually declined during the first 5 months in infants. Infection of EV71 was most likely to occur between 2 and 4 years. Our findings may be useful in informing population-based EV71 vaccination strategies.
authors.affiliation: From the *School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China; and †Division of Infectious Disease, Key Laboratory of Surveillance and Early-Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Bingyi
authors.initials: B
authors.lastname: Yang
authors.forename: Peng
authors.initials: P
authors.lastname: Wu
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Wu
authors.forename: Eric H Y
authors.initials: EH
authors.lastname: Lau
authors.forename: Gabriel M
authors.initials: GM
authors.lastname: Leung
authors.forename: Hongjie
authors.initials: H
authors.lastname: Yu
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Cowling
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D029821:Enterovirus A, Human; D006232:Hand, Foot and Mouth Disease / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016036:Seroepidemiologic Studies