title: [Analysis of seroepidemiology of enterovirus 71 diseases in children in Jiangsu province].
abstract: OBJECTIVE
  To analyze the dynamic pattern and the distributive characteristics of neutralizing antibody against enterovirus 71 (EV-A71 ) in children aged 6-35 months in Jiangsu province from 2012 to 2014.
  
  
  METHODS
  From March, 2012 to March, 2014, a total of 1 276 children aged between 6 and 35 months were regularly followed up on day 0, year 1 and year 2 for EV-A71 neutralizing antibody test based on the enterovirus surveillance system, with the method of reporting by their guardian or being visited in Ganyu Sheyang Taixing Donghai Pizhou and Baoying in Jiangsu province. At the same time, samples were taken from the suspected persons infected by enterovirus. The χ(2) test or variance analysis was used to compare the difference of the positive rates and the geometric mean titer(GMT) of EV-A71 neutralizing antibody in different subjects.
  
  
  RESULTS
  In 2 years follow-up, the positive rates of EV-A71 antibody increased as the growth of the age,and the positive rates on day 0, year 1 and year 2 were 22.57% (288/1 276), 37.72%(444/1 177) and 42.84%(422/985), respectively (χ(2) values were 39.33, 56.41, 32.25; P< 0.001).The GMTs were 9.95, 15.37 and 24.05, respectively (F values were 22.90,46.36,41.58;P<0.001). In 2 years, the annually new infection rates were 13.47%(158/1 173) and 20.73%(192/926),respectively, and the annually decay rates of EV-A71 antibody were 2.81%(33/1 173) and 8.10%(75/926).
  
  
  CONCLUSIONS
  In 2012 to 2014, the positive rates and the GMTs of EV-A71 antibody of children increased as the growth of the age in Jiangsu. The higher annually new infection rate was in children aged 3 to 4 years. The EV-A71 neutralizing antibody level could maintain at least two years after natural infection.
authors.affiliation: School of Public Health, Southeast University, Nanjing 210009, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhou
authors.forename: Jingxin
authors.initials: J
authors.lastname: Li
authors.forename: Fanyue
authors.initials: F
authors.lastname: Meng
authors.forename: Yuemei
authors.initials: Y
authors.lastname: Hu
authors.forename: Pengfei
authors.initials: P
authors.lastname: Jin
authors.affiliation: Email: njzhangxf@126.com.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Email: jszfc@vip.sina.com.
authors.forename: Fengcai
authors.initials: F
authors.lastname: Zhu
mesh_terms: D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D029821:Enterovirus A, Human; D004769:Enterovirus Infections / Q000097:blood*; D006801:Humans; D007223:Infant; D016036:Seroepidemiologic Studies
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral