Background

• Neisseria meningitidis, Haemophilus influenzae type b (Hib), and Streptococcus pneumoniae constitute the majority of all cases of bacterial meningitis and 90% of bacterial meningitis in children.
• Meningococcal meningitis is the main form of meningitis causing epidemics and remains a major public health challenge in the African meningitis belt, an area that extends from Senegal to Ethiopia. In these countries, large outbreaks may occur during the dry season (November through May). Outside of the meningitis belt, smaller outbreaks may occur year-round.
• Epidemics in the meningitis belt were traditionally associated with Neisseria meningitidis serogroup A before the introduction of a meningococcal A conjugate vaccine (MACV) (MenAfriVac vaccine) into meningitis belt countries starting in 2010. MACV is immunogenic in both infants and adults and confers long-term protection. It has dramatically reduced the circulation of Nm A and eliminated Nm A epidemics.
• Epidemics from other serogroups continue to occur: since 2013 major epidemics due to Nm serogroup C occurred in Nigeria and Niger. From 2016 to 2018, major mixed epidemics of Neisseria meningitidis serogroup W and Streptococcus pneumoniae have been reported in Ghana. In 2016 and 2017 Togo reported epidemics due to Nm serogroup W. In addition, in 2006 Burkina and Niger reported an epidemic due to Nm serogroup X.
• Human-to-human disease transmission is via large respiratory droplets from the nose and throats of infected people.
• Incubation period is 2 to 10 days.
• Attack rates are highest among children aged less than 15 years. Case fatality rates are usually 8-15% among treated patients, and >70% among untreated cases. Many survivors suffer long-term sequelae including mental retardation, hearing loss and loss of limb use.
• Ceftriaxone is the drug of choice for treatment during epidemics because it is effective on the predominant meningitis pathogens. In addition, antimicrobial resistance to ceftriaxone has not yet been detected in Africa.
• During epidemics in the meningitis belt, antibiotic prophylaxis is not recommended
• The current response to meningitis epidemics consists of reactive mass vaccination campaigns with bivalent (A C) or trivalent/quadrivalent polysaccharide vaccine (A, C, W/ A, C, Y W) as soon as possible after an epidemic has been declared. Polysaccharide vaccines do not protect very young children (<2 years) and only provide protection for up to three years.