title: Measles outbreak in Northern Central African Republic 3 years after the last national immunization campaign.
abstract: BACKGROUND
  Despite huge efforts to promote widespread vaccination, measles remains an important cause of morbidity and mortality worldwide, especially in African children. In March 2011, an abnormally high number of cases were reported from the Ouham Prefecture, Central African Republic to the national measles case-based surveillance system. In response, reactive vaccination activities were implemented. The aims of this study were to investigate this outbreak and describe the response.
  
  
  METHODS
  Measles cases were defined according to WHO recommendations. In the first weeks of the outbreak, blood samples were collected and sent to the Institut Pasteur in Bangui for laboratory confirmation by detection of IgM antibodies against measles virus. In addition, a portion of viral RNA was amplified from 5 IgM positive patient samples and the amplicons were sequenced for phylogenetic analysis.
  
  
  RESULTS
  Between March and September 2011, 723 clinical cases originated from the Ouham Prefecture, including 2 deaths, were reported. Amongst 59 blood samples collected, 49 were positive for the detection of IgM. A high number of self-declared vaccinated subjects (31%) were found amongst the cases. Most of the cases were under 5 years. The causative virus was found to belong to genotype B3.1. In response, 2 sub-national supplementary immunization activities were quickly conducted and limited this outbreak to mainly 2 sub-prefectures.
  
  
  CONCLUSIONS
  This outbreak was the largest epidemic of measles in CAR since 2002. Its occurrence, 3 years after the last national immunization campaign, highlights the necessity to pursue efforts and improve and extend immunization programs in order to reach measles elimination goal in Africa.
authors: Institut Pasteur de Bangui, Bangui, Central African Republic. vianney.tricou@gmail.com
authors: Vianney
authors: V
authors: Tricou
authors: Marilou
authors: M
authors: Pagonendji
authors: Casimir
authors: C
authors: Manengu
authors: Jeff
authors: J
authors: Mutombo
authors: Rock Ouambita
authors: RO
authors: Mabo
authors: Ionela
authors: I
authors: Gouandjika-Vasilache
mesh_terms: D000293:Adolescent; D000914:Antibodies, Viral / Q000097:blood; D002488:Central African Republic / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks / Q000517:prevention & control / Q000706:statistics & numerical data*; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D032541:Mass Vaccination; D008457:Measles / Q000097:blood / Q000453:epidemiology* / Q000517:prevention & control; D008458:Measles Vaccine / Q000008:administration & dosage*; D010802:Phylogeny
chemical_list: D000914:Antibodies, Viral; D007075:Immunoglobulin M; D008458:Measles Vaccine