Chronicle of an outbreak foretold: meningococcal meningitis W135 in Burkina Faso.

Burkina Faso lies within the African meningitis belt. Until recently, serogroup A of Neisseria meningitidis was the most common cause of epidemic meningitis in Burkina Faso. However, during the epidemic that started in January 2002, W135 was the predominant serogroup of meningococcus. Vaccine against the W135 serogroup is expensive and in short supply. Strategies to react to a future African epidemic of W135 meningococcal meningitis with a sufficient and affordable supply of vaccine must be put into place now.