title: [Epidemiological characteristics of enterovirus type 71 diseases].
abstract: OBJECTIVE
  The objective of this study was to investigate the epidemiological characteristics of disease caused by enterovirus type 71.
  
  
  METHODS
  A total of 10 158 children aged between 6 and 35 months, were recruited from 7 sites where EV71 inactivated vaccine phase 3 clinical trial was carried out. All the subjects were followed up to one year to investigate the epidemiological characteristics of the disease caused by EV71.
  
  
  RESULTS
  The accumulate incidence density of disease caused by EV71 was 15.17/1 000 person-year. Of all the cases, hand, foot and mouth disease (HFMD), herpangina, respiratory system diseases, digestive system diseases and other diseases accounted for 82.00%, 2.67%, 13.33%, 1.33% and 0.67%, respectively. The difference of the incidence density between boys and girls showed no statistical significance. Majority of the patients were between 12 and 23 months of age, which accounted for 58.67% of the total patients. The differences of incidence density between different months of age were statistically significant (χ(2) = 7.789, P = 0.020). The peak incidence density of disease caused by EV71 occurred from April to June. Nine cases showed severe symptoms or signs that accounted for 6.00% of all the cases. All severe cases were identified as HFMD, of which 7 were boys and 2 were girls. The number of severe cases in different months of age appeared to be 1, 7, and 1, all occurred between April and June. The median courses of HFMD cases and non-HFMD cases were 9 and 6 days, with difference statistically significant (Z = -4.000, P < 0.001). Median of excretion cycle for HFMD and non-HFMD cases were 9 and 11 days respectively. But with no statistically significant difference between the two.
  
  
  CONCLUSIONS
  Majority of the disease that caused by EV71 appeared as HFMD. Most of them were younger children and with seasonal variation.
authors: School of Public Health, Southeast University, Nanjing 210009, China.
authors: Zhengkai
authors: Z
authors: Gan
authors: Jiangsu Provincial Center for Disease Control and Prevention.
authors: Jingxin
authors: J
authors: Li
authors: Jiangsu Provincial Center for Disease Control and Prevention.
authors: Fanyue
authors: F
authors: Meng
authors: Jiangsu Provincial Center for Disease Control and Prevention.
authors: Yuemei
authors: Y
authors: Hu
authors: School of Public Health, Nanjing Medical University.
authors: Xuejun
authors: X
authors: Yao
authors: Jiangsu Provincial Center for Disease Control and Prevention. Email: njzhangxf@126.com.
authors: Xuefeng
authors: X
authors: Zhang
authors: Jiangsu Provincial Center for Disease Control and Prevention. Email: jszfc@vip.sina.com.
authors: Fengcai
authors: F
authors: Zhu
mesh_terms: D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D002980:Climate; D004066:Digestive System Diseases; D004770:Enterovirus; D004769:Enterovirus Infections / Q000453:epidemiology*; D005260:Female; D006232:Hand, Foot and Mouth Disease / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D010808:Physical Examination; D012621:Seasons