Manson Lecture. Meningococcal meningitis in Africa.

This review covers the history of meningococcal meningitis in Africa since epidemics of the infection were first described around 100 years ago. It is possible that an epidemic strain of the meningococcus was introduced into West Africa from the Sudan by pilgrims returning from the Haj around the turn of the century. Since 1905 major epidemics of meningococcal meningitis have occurred in countries of the Sahel and sub-Sahel every few years, culminating in a massive epidemic in which nearly 200,000 cases were reported in 1996. Attempts to control epidemic meningococcal meningitis in Africa by vaccination with meningococcal polysaccharide vaccines have met with only modest success because epidemics can progress with great rapidity and vaccination is often started too late. This situation should be improved as a result of a recent initiative, the International Coordinating Group (ICG), which is contributing to better surveillance in countries at risk and ensuring that vaccine is available when needed. However, in the medium term, the best prospect for the control of meningococcal meningitis in Africa lies in the recent development of polysaccharide-protein conjugate vaccines which, unlike polysaccharide vaccines, are immunogenic in the very young, induce immunological memory and are likely to give long-lasting protection.