title: Large measles outbreak at a German public school, 2006.
abstract: BACKGROUND
  In 2006, a large measles outbreak (n = 614) occurred in Duisburg city, Germany, with 54% of cases aged >9 years. An investigation was launched to determine reasons for the resurgence of measles, assess vaccination coverage and vaccine effectiveness (VE).
  
  
  METHODS
  A retrospective cohort-study was undertaken at a Duisburg public school affected early in the outbreak. We distributed questionnaires to all 1250 students aged 10-21 years and abstracted vaccination records. Cases were identified according to a standard clinical case definition.
  
  
  RESULTS
  Questionnaires were returned by 1098 (88%) students. Vaccination records were abstracted from 859 students, of whom 820 (95.4%) had received at least one, 605 (70.4%) 2, and 39 (4.5%) no dose(s) of measles-containing vaccine (MCV). Coverage with 2 doses was higher in younger students. We identified 53 cases (attack rate = 5%). Measles-virus sequencing revealed genotype D6. After excluding students vaccinated in 2006 and those with a history of measles, the attack rate was 53% in unvaccinated students, 1.0% in students with one, and 0.4% in those with 2 MCV-doses. VE was 98.1% (95% CI: 92-100%) in students with one and 99.4% (95% CI: 97-100%) with 2 MCV-doses. Based on observed attack rates in vaccinated and unvaccinated students with vaccination records and in students without vaccination records, one-dose-coverage among all participating students was estimated at 91%.
  
  
  CONCLUSIONS
  VE was high. Vaccination coverage was, however, insufficient to prevent the outbreak. Immunization gaps were found especially in older students. To prevent further outbreaks and to achieve the goal of measles elimination in Germany, vaccination coverage must be increased.
authors.affiliation: Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany. wichmannO@rki.de
authors.forename: Ole
authors.initials: O
authors.lastname: Wichmann
authors.forename: Wiebke
authors.initials: W
authors.lastname: Hellenbrand
authors.forename: Daniel
authors.initials: D
authors.lastname: Sagebiel
authors.forename: Sabine
authors.initials: S
authors.lastname: Santibanez
authors.forename: Gabriele
authors.initials: G
authors.lastname: Ahlemeyer
authors.forename: Georg
authors.initials: G
authors.lastname: Vogt
authors.forename: Anette
authors.initials: A
authors.lastname: Siedler
authors.forename: Ulrich
authors.initials: U
authors.lastname: van Treeck
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D015331:Cohort Studies; D004196:Disease Outbreaks / Q000517:prevention & control; D005858:Germany / Q000453:epidemiology; D006801:Humans; D007115:Immunization Schedule; D008457:Measles / Q000453:epidemiology* / Q000517:prevention & control*; D008458:Measles Vaccine / Q000008:administration & dosage*; D008499:Medical Records; D012574:Schools; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D014611:Vaccination / Q000706:statistics & numerical data*
chemical_list: D008458:Measles Vaccine