Serogroup-Specific Characteristics of Localized Meningococcal Meningitis Epidemics in Niger 2002-2012 and 2015: Analysis of Health Center Level Surveillance Data

PLoS One. 2016 Sep 22;11(9):e0163110. doi: 10.1371/journal.pone.0163110. eCollection 2016.

Abstract

To compare dynamics of localized meningitis epidemics (LE) by meningococcal (Nm) serogroup, we analyzed a surveillance database of suspected and laboratory-confirmed Nm cases from 373 health areas (HA) of three regions in Niger during 2002-2012 and one region concerned by NmC epidemics during 2015. We defined LE as HA weekly incidence rates of ≥20 suspected cases per 100,000 during ≥2 weeks and assigned the predominant serogroup based on polymerase chain reaction testing of cerebrospinal fluid. Among the 175 LE, median peak weekly incidence rate in LE due to NmA, W, X and C were 54, 39, 109 and 46 per 100,000, respectively. These differences impacted ability of the epidemic to be detected at the district level. While this analysis is limited by the small number of LE due to NmX (N = 4) and NmW (N = 5), further research should explore whether strategies for prevention and response to meningitis epidemics need to be adapted according to predominant meningococcal serogroups.

Grants and funding

This work was supported by the Office of International Cooperation of the Principality of Monaco. Surveillance activities were funded by the Ministère Français des Affaires Etrangères (Fonds de Solidarité Prioritaire), Sanofi Pasteur and the « Ministère de la Santé Publique du Niger/Fonds commun» and CDC/MenAfriNet. The “Cooperation Technique Belge” funded the first health area map’s support.