title: Epidemic of measles following the nationwide mass immunization campaign.
abstract: BACKGROUND
  A prolonged measles epidemic occurred in Wenzhou City, China after a nationwide measles mass immunization campaign (MMIC) in 2010. We conducted an investigation to identify factors contributing to this epidemic and to provide evidence-based recommendations for measles elimination strategies in China.
  
  
  METHODS
  Measles was diagnosed using the national standard case-definitions. We estimated the population vaccination coverage based on the proportion of measles patients that had been vaccinated. In a case-control investigation, all measles patients who received treatment in The Second Affiliated Hospital of Wenzhou Medical College (Hospital S) during November 1 to December 31, 2010 served as cases; controls were randomly selected among all other patients who received treatment in Hospital S during the same time period, frequency matched by month of hospital visit. We reviewed medical records of case- and control-patients to compare their exposure history at Hospital S and to its intravenous rehydration room (IV room) during the incubation period (7-21 days before their illness onset).
  
  
  RESULTS
  The attack rate of measles in Wenzhou City was 3.3/100,000 during September 1, 2010 to January 11, 2011. Children aged 8-11 m had the highest attack rate (171/100,000) of all age groups. In children not age-eligible for the MMIC but should have been routinely vaccinated after the MMIC, the vaccination rate was only 52%. In the case-control investigation, 60% (25/42) of case-patients compared with 21% (35/168) of control-patients had visited Hospital S (adjusted ORM-H = 5.5, 95% CI = 2.7-11). Among unvaccinated children who had received treatment in Hospital S, 84% (21/25) of case-patients compared 38% (11/29) of control-patients had visited the IV room (adjusted ORM-H = 9.2, 95% CI = 1.5-59).
  
  
  CONCLUSIONS
  Relaxed routine measles vaccination among children after the MMIC was the main factor responsible for this epidemic. Exposure in the IV room at Hospital S facilitated the epidemic. To reach the goal of measles elimination, the Chinese public health authorities should make greater efforts to improve timely routine measles vaccination, and to reduce nosocomial transmission.
authors.affiliation: Jing’an District Center for Disease Control and Prevention, Shanghai City, People’s Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Gao
authors.forename: Enfu
authors.initials: E
authors.lastname: Chen
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Wang
authors.forename: Jichuan
authors.initials: J
authors.lastname: Shen
authors.forename: Hanqing
authors.initials: H
authors.lastname: He
authors.forename: Huilai
authors.initials: H
authors.lastname: Ma
authors.forename: Guang
authors.initials: G
authors.lastname: Zeng
authors.forename: Bao-Ping
authors.initials: BP
authors.lastname: Zhu
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003428:Cross Infection / Q000453:epidemiology / Q000635:transmission; D058872:Epidemics; D006761:Hospitals; D006801:Humans; D007223:Infant; D032541:Mass Vaccination; D008457:Measles / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission; D008458:Measles Vaccine / Q000008:administration & dosage*; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors
chemical_list: D008458:Measles Vaccine