Meningococcal Meningitis Surveillance in the African Meningitis Belt, 2004-2013

Clin Infect Dis. 2015 Nov 15;61 Suppl 5(Suppl 5):S410-5. doi: 10.1093/cid/civ597.

Abstract

Background: An enhanced meningitis surveillance network was established across the meningitis belt of sub-Saharan Africa in 2003 to rapidly collect, disseminate, and use district weekly data on meningitis incidence. Following 10 years' experience with enhanced surveillance that included the introduction of a group A meningococcal conjugate vaccine, PsA-TT (MenAfriVac), in 2010, we analyzed the data on meningitis incidence and case fatality from countries reporting to the network.

Methods: After de-duplication and reconciliation, data were extracted from the surveillance bulletins and the central database held by the World Health Organization Inter-country Support Team in Burkina Faso for countries reporting consistently from 2004 through 2013 (Benin, Burkina Faso, Chad, Democratic Republic of Congo, Ghana, Côte d'Ivoire, Mali, Niger, Nigeria, Togo).

Results: The 10 study countries reported 341 562 suspected and confirmed cases over the 10-year study period, with a marked peak in 2009 due to a large epidemic of group A Neisseria meningitidis (NmA) meningitis. Case fatality was lowest (5.9%) during this year. A mean of 71 and 67 districts annually crossed the alert and epidemic thresholds, respectively. The incidence rate of NmA meningitis fell >10-fold, from 0.27 per 100,000 in 2004-2010 to 0.02 per 100,000 in 2011-2013 (P < .0001).

Conclusions: In addition to supporting timely outbreak response, the enhanced meningitis surveillance system provides a global overview of the epidemiology of meningitis in the region, despite limitations in data quality and completeness. This study confirms a dramatic fall in NmA incidence after the introduction of PsA-TT.

Keywords: Africa; meningitis; surveillance.

MeSH terms

  • Africa South of the Sahara / epidemiology
  • Epidemiological Monitoring*
  • Humans
  • Incidence
  • Meningitis, Meningococcal / epidemiology*
  • Mortality
  • Neisseria meningitidis / classification*
  • Neisseria meningitidis / isolation & purification*