Meningococcal meningitis is an infection that causes inflammation of the membranes covering the brain and spinal cord.

Meningococcal meningitis is caused by the bacterium Neisseria meningitidis (also known as meningococcus).

Most cases of meningococcal meningitis occur in children, from infancy to adolescence. Meningococcus is the most common cause of bacterial meningitis in children and the second most common cause of bacterial meningitis in adults.

The onset of the disease may be rapid and may start with an upper respiratory infection or sore throat. The infection occurs more often in winter or spring and may cause local epidemics at boarding schools, college dormitories, or military bases.

Risk factors include recent exposure to meningococcal meningitis and recent upper respiratory infection.

• Rash, pinpoint red spots (petechiae)
• Purple, bruise-like areas (purpura)
• High fever
• Severe headache
• Severe malaise (general ill feeling)
• Nausea
• Vomiting
• Stiff neck
• Sensitivity to light (photophobia)
• Mental status changes

Physical examination will reveal low blood pressure, fast heart rate, stiff neck, and a possible rash.

Other tests include the following:

• White blood cell (WBC) count is higher than normal.
• Spinal tap for spinal fluid (CSF) shows increased white blood cells, low glucose, high protein.
• Special stains of spinal fluid sometimes show the meningococcus bacteria.
• CSF culture grows the meningococcus bacteria.
• Blood culture grows the meningococcus bacteria.
• CT scan of the brain is usually normal.