Meningococcal meningitis: Inflammation of the meninges due to infection with the bacterium Neisseria meningitidis. Meningococcal meningitis typically starts like the flu, with the sudden onset of an intense headache, fever, sore throat, nausea, vomiting, and malaise. But, unlike with the flu, a stiff neck and intolerance of lights are frequent symptoms of meningococcal meningitis. Within hours of the first symptoms, the disease can progress to delirium, coma, or convulsions and invade the bloodstream, setting off a bodywide infection that attacks organs and can cause circulatory collapse, a hemorrhagic rash, and gangrene. Meningococcal meningitis is a medical emergency. Diagnosis is made through examination of the CSF obtained via lumbar puncture. Treatment includes use of appropriate antibiotics, usually in the hospital. The disease is highly contagious; it is spread by contact with an affected individual's respiratory secretions, such as by coughing or kissing. Meningococcal meningitis has a high fatality rate if not recognized and treated properly. Vaccines against four types of meningococcal disease are available and are recommended for at-risk persons, including college freshmen living in dormitories.