Meningococcal meningitis is caused by Neisseria meningitidis and is a contagious and potentially fatal bacterial infection of the meninges, the thin lining surrounding the brain and spinal cord. People can be infected and carry the disease without showing symptoms, spreading the bacteria to others through droplets of respiratory or throat secretions, for example when they cough or sneeze. The infection can also cause sudden and intense headaches, fever, nausea, vomiting, sensitivity to light and stiffness of the neck. Death can follow within hours of the onset of symptoms.
Without proper treatment, bacterial meningitis kills up to half of those infected. Suspected cases are properly diagnosed through examination of a sample of spinal fluid and treated with a range of antibiotics. Even when given appropriate antibiotic treatment, five to ten percent of people with meningitis will die and as many as one out of five survivors may suffer from after-effects ranging from hearing loss to learning disabilities.
Meningitis occurs sporadically throughout the world, but the majority of cases and deaths are in Africa, particularly across an east-west geographical strip from Senegal to Ethiopia, the "meningitis belt" where outbreaks occur regularly. Vaccination is the recognised way to protect people from the disease.
MSF treated 5,337 and vaccinated 1.8 million people against meningitis in 2006.