An infection caused by meningococcus bacterium, which causes inflammation of the membranes covering the brain and spinal cord.
Most cases occur in children from infancy to adolescence.
The onset may be rapid, and may follow an upper respiratory infection . The infection occurs in winter or spring, and may cause local epidemics at boarding schools or military bases. Risk factors are exposure to meningococcal meningitis, and recent upper respiratory infection. The incidence is 1 out of 1,000,000 people. Please read this Important notice .