Control of meningococcal meningitis outbreaks in sub-Saharan Africa.

Outbreaks of Neisseria meningitidis recur frequently in the African Sahel where they are responsible for high mortality and morbidity, especially in children. An effective vaccine has been in existence for more than 30 years, but despite this, the control of epidemics has failed. Moreover, the geographical distribution of N. meningitidis seems to be increasing, perhaps because of climate change but also because of the economic crisis which prevails throughout much of Africa leading to population movements and the breakdown of essential services. Although alarming, the emergence of new serogroups in recent epidemics (such as serogroups X and W135) should not mask the fact that serogroup A remains the most common meningococcal isolate from meningitis cases and is therefore the most significant target for control. The development of a low-cost conjugate meningococcal vaccine should support a strategy of preventive immunization, as this strategy is one that appears most effective to control this plague.