Laboratoire de météorologie dynamique (LMD), École polytechnique, RD 36, 91128 Palaiseau cedex <sultanlmd.polytechnique.fr> Université de Paris 7 Denis Diderot, UFR GHSS GHSS (c.c. 7001), Dynamique des milieux et risques, 2, place Jussieu, 75251 Paris cedex 05 <beltrandoparis7.jussieu.fr>
Each year a meningitis epidemic in West Africa strikes between 25,000 and 200,000 members of one of the world‘s poorest populations. The timing of the epidemic year, which begins in February and ends in late May, and its spatial distribution throughout the "Meningitis Belt" are closely related to climate. This study uses weekly reports of cases and deaths due to meningococcal meningitis (MCM) from the World Health Organization (WHO) and atmospheric reanalyses from NCEP‐NCAR to document the relation between the seasonal course of MCM cases and large‐scale atmospheric circulation. Regional atmospheric indexes constructed from measurements of specific humidity and surface wind at 1,000 hPa show the similarity of the temporal patterns of epidemics and climate: the onset of epidemics and the winter maximum temperature share the same mean week (6th week of the year) and are significantly correlated (0.92). Although these events coincide, the analysis does not show any significant relation between the intensity of the epidemic and of the winter maximum.