A hypothetical explanatory model for meningococcal meningitis in the African meningitis belt

Example of weekly incidence rates (per 100 000, 4-week moving average) of notified suspected meningitis cases and air humidity in the meningitis belt. Sanitary districts Secteur 15 (400 000 inhabitants) and Houndé (250 000 inhabitants) in western Burkina Faso, 1997–2008. Data: Direction Régionale de Santé des Hauts-Bassins, Burkina Faso. (a) Scale of y-axis up to 5 per 100 000; hatched line, relative air humidity measured at the Bobo-Dioulasso airport during 2006. All districts experience hyperendemic incidences of about 1 per 100 000 during all years. (b) Scale of y-axis up to 80 per 100 000. Epidemics were declared at the district level only during some years (here during 1996, 2002, and 2006).

Annual total number of reported suspected meningitis cases, Burkina Faso, 1940–2008. Data: Ministry of Health, Burkina Faso.

Hypothetical explanatory model for meningococcal meningitis in the African meningitis belt.