Antecedent causes of a measles resurgence in the Democratic Republic of the Congo

  • Heather Melissa Scobie
  • Benoît Kebela Ilunga
  • Audry Mulumba
  • Calixte Shidi
  • Tiekoura Coulibaly
  • Ricardo Obama
  • Jean- Jacques Muyembe Tamfum
  • Elisabeth Pukuta Simbu
  • Sheilagh Brigitte Smit
  • Balcha Masresha
  • Robert Tyrrell Perry
  • Mary Margaret Alleman
  • Katrina Kretsinger
  • James Goodson
Keywords: Measles, outbreak, elimination, immunization, vaccination, surveillance, DRC, RDC

Abstract

Introduction: Despite accelerated measles control efforts, a massive measles resurgence occurred in the Democratic Republic of the Congo (DRC) starting in mid-2010, prompting an investigation into likely causes. Methods: We conducted a descriptive epidemiological analysis using measles immunization and surveillance data to understand the causes of the measles resurgence and to develop recommendations for elimination efforts in DRC. Results: During 2004-2012, performance indicator targets for case-based surveillance and routine measles vaccination were not met. Estimated coverage with the routine first dose of measles-containing vaccine (MCV1) increased from 57% to 73%. Phased supplementary
immunization activities (SIAs) were conducted starting in 2002, in some cases with sub-optimal coverage (≤95%). In 2010, SIAs in five of 11 provinces were not implemented as planned, resulting in a prolonged interval between SIAs, and a missed birth cohort in one province. During July 1, 2010-December 30, 2012, high measles attack rates (>100 cases per 100,000 population) occurred in provinces that had estimated MCV1 coverage lower than the national estimate and did not implement planned 2010 SIAs. The majority of confirmed case-patients were aged <10 years (87%) and unvaccinated or with unknown vaccination status (75%). Surveillance detected two genotype B3 and one genotype B2 measles
virus strains that were previously identified in the region. Conclusion: The resurgence was likely caused by an accumulation of unvaccinated, measles-susceptible children due to low MCV1 coverage and suboptimal SIA implementation. To achieve the regional goal of measles elimination by 2020, efforts are needed in DRC to improve case-based surveillance and increase two-dose measles vaccination coverage through routine services and SIAs.

Keywords: Measles, outbreak, elimination, immunization, vaccination, surveillance, DRC, RDC

Published
2016-03-22
Section
Articles

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eISSN: 1937-8688