Meningitis disease is an infection of the meninges, the membrane covering the brain. Bacterial meningitis is very serious because its onset is rapid and the infection is associated with a significant risk of death; it may also result in mental retardation, deafness, epilepsy, etc. It can be treated with appropriate antibiotics that also prevents spread.
Neisseria meningitidis only infects humans; there is no animal reservoir. The bacteria can be carried in the throat and sometimes, for reasons not fully understood, can overwhelm the body's defenses allowing infection to spread through the bloodstream to the brain. It is believed that 10% to 20% of the population carries Neisseria meningitidis in their throat at any given time. However, the carriage rate may be higher in epidemic situations.
A range of antibiotics can treat the infection, including penicillin, ampicillin, chloramphenicol and ceftriaxone. Under epidemic conditions in Africa in areas with limited health infrastructure and resources, ceftriaxone is the drug of choice.
1. Polysaccharide vaccines have been available to prevent the disease for over 30 years. Meningococcal polysaccharide vaccines are available in either bivalent (groups A and C), trivalent (groups A, C and W), or tetravalent (groups A, C, Y and W) forms to control the disease.
2. For group B, polysaccharide vaccines cannot be developed, due to antigenic mimicry with polysaccharide in human neurologic tissues. The first vaccine against NmB, made from a combination of 4 protein components, was released in 2014.
3. Since 1999, meningococcal conjugate vaccines against group C have been available and widely used. Tetravalent A, C, Y and W conjugate vaccines have been licensed since 2005 for use in children and adults in Canada, the United States of America, and Europe.