title: Measles epidemic from 1951 to 2012 and vaccine effectiveness in Guangzhou, southern China.
abstract: BACKGROUND
  Since the National Expanded Program on Immunization was implemented in China, considerable progress has been made in reducing the incidence of measles. However, the incidence of measles increased again in 2004. Few post-marketing studies on measles vaccine effectiveness were reported in China. In this study, we aimed to describe the measles epidemic and to evaluate the effectiveness of the measles vaccine in Guangzhou, southern China.
  
  
  METHODS
  Based on the surveillance data for measles, we investigated the epidemiology during different periods between 1951 and 2012. We analyzed the clinical characteristics of laboratory-confirmed cases of measles between 2009 and 2012 and conducted a case-control study using test-negative cases as controls. We determined the protective effect of measles vaccine.
  
  
  RESULTS
  The highest annual incidence in Guangzhou was 2187.15/100,000 in 1964, and the lowest was 0.32/100,000 in 2011. The average incidence of measles from 1951 to 2012 was 306.27/100,000. There was a significant tendency of decline in recent years. From 2009 to 2012, there are 700 laboratory-confirmed cases were reported with an average onset age of 2.5 (median) years. The non-vaccinated target population (age<8 months and ≥ 15 years) accounted for 56.7% of the cases. The transient (non-resident) population accounted for 51.3% of the cases. Fewer cases were observed in the population targeted for measles vaccine (aged 8 months to 14 years). The effectiveness of a single dose of the measles vaccine was 89.1% (95% confidence interval (CI), 44.5-97.9), and the effectiveness of ≥ 2 doses of the measles vaccine was 97.8% (95% CI, 88.3-99.6) in children aged 8 months to 14 years old.
  
  
  CONCLUSIONS
  There is a significant overall decline in the incidence of measles (including clinical and laboratory confirmed cases) in the measles vaccine targeted population in Guangzhou. Two doses of measles vaccine are more effective than one dose in preventing measles in China. In order to accelerate the elimination of measles, vaccination should also be given to the transient and the non-vaccine targeted population.
authors: Guangzhou Center for Disease Control and Prevention; Guangzhou, PR China.
authors: Zhicong
authors: Z
authors: Yang
authors: Guangzhou Center for Disease Control and Prevention; Guangzhou, PR China.
authors: Jianxiong
authors: J
authors: Xu
authors: Guangzhou Center for Disease Control and Prevention; Guangzhou, PR China.
authors: Ming
authors: M
authors: Wang
authors: Guangzhou Center for Disease Control and Prevention; Guangzhou, PR China.
authors: Biao
authors: B
authors: Di
authors: Guangzhou Center for Disease Control and Prevention; Guangzhou, PR China.
authors: Huifeng
authors: H
authors: Tan
authors: Guangzhou Center for Disease Control and Prevention; Guangzhou, PR China.
authors: Qing
authors: Q
authors: He
authors: Guangzhou Center for Disease Control and Prevention; Guangzhou, PR China.
authors: Yanshan
authors: Y
authors: Cai
authors: Guangzhou Center for Disease Control and Prevention; Guangzhou, PR China.
authors: Jianhua
authors: J
authors: Liang
authors: Guangzhou Center for Disease Control and Prevention; Guangzhou, PR China.
authors: Wensui
authors: W
authors: Hu
authors: Guangzhou Center for Disease Control and Prevention; Guangzhou, PR China.
authors: Zhiqiang
authors: Z
authors: Dong
authors: School of Public Health, Shandong University, Jinan, PR China.
authors: Yunqing
authors: Y
authors: Yang
authors: Guangzhou Center for Disease Control and Prevention; Guangzhou, PR China.
authors: Chuanxi
authors: C
authors: Fu
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D058872:Epidemics; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008457:Measles / Q000453:epidemiology* / Q000517:prevention & control*; D008458:Measles Vaccine / Q000008:administration & dosage* / Q000276:immunology*; D016896:Treatment Outcome; D014611:Vaccination / Q000379:methods / Q000706:statistics & numerical data
chemical_list: D008458:Measles Vaccine
keywords: China; case-control studies; measles elimination; measles epidemic; vaccine effectiveness