title: Migration as a risk factor for measles after a mass vaccination campaign, Burkina Faso, 2002.
abstract: BACKGROUND
  Shortly after a measles supplementary immunization activity (SIA) targeting children from 9 months to 14 years of age that achieved high coverage, Burkina Faso had a large, serologically confirmed measles outbreak. To investigate the causes of this first reported failure of a widely successful measles control strategy we conducted a case-control study.
  
  
  METHODS
  Serologically confirmed measles cases aged > or =9 months at the time of the SIA in 6 heavily affected districts were frequency matched on age to 3 controls recruited from people frequenting health centres in the same districts.
  
  
  RESULTS
  Between January and July 2002, 1287 measles cases were reported throughout Burkina Faso. Of the 707 cases that were serologically confirmed, 358 (51%) were from 9 months to 14 years of age and 265 (37%) were > or =15 years of age. Among cases and controls from 9 months to 14 years of age significant risk factors for measles were lack of measles vaccination and, in the unvaccinated, recent travel to Cote d'Ivoire. Of the recent measles cases in Cote d'Ivoire 54% were there when exposed to measles. Among adults, risk factors included non-vaccination and the lack of school attendance during childhood. Vaccine effectiveness was estimated to be 98%.
  
  
  CONCLUSIONS
  Migration of children between Cote d'Ivoire and Burkina Faso played a major role in the failure of the SIA to interrupt measles transmission. Synchronization of measles control activities should be a high priority in countries with regions where much migration occurs.
authors.affiliation: Health Information System, Directorate of Studies and Planning, Ministry of Health, Ouagadougou, Burkina Faso.
authors.forename: K Robert
authors.initials: KR
authors.lastname: Yaméogo
authors.forename: Robert T
authors.initials: RT
authors.lastname: Perry
authors.forename: André
authors.initials: A
authors.lastname: Yaméogo
authors.forename: Chantal
authors.initials: C
authors.lastname: Kambiré
authors.forename: M Kader
authors.initials: MK
authors.lastname: Kondé
authors.forename: Déogratias
authors.initials: D
authors.lastname: Nshimirimana
authors.forename: Robert
authors.initials: R
authors.lastname: Kezaala
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Hersh
authors.forename: K Lisa
authors.initials: KL
authors.lastname: Cairns
authors.forename: Peter
authors.initials: P
authors.lastname: Strebel
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D002050:Burkina Faso / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D004641:Emigration and Immigration; D005191:Family Characteristics; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008457:Measles / Q000453:epidemiology* / Q000517:prevention & control; D008458:Measles Vaccine / Q000008:administration & dosage*; D011159:Population Surveillance / Q000379:methods; D012307:Risk Factors; D014195:Travel; D014611:Vaccination / Q000379:methods*
chemical_list: D008458:Measles Vaccine