Meningococcal disease is a rapidly progressive infection caused by Neisseria meningitides, a Gram-negative diplococcus bacterium. Infection begins as a nonspecific viral-like illness that rapidly evolves (within hours) into one of two main presentations: meningitis or septicemia. Apart from epidemics, meningococcal disease occurs sporadically, most commonly during the winter months, often following outbreaks of influenza. Most cases are acquired through exposure to asymptomatic carriers via respiratory droplets. Although severe disease has a mortality approaching 50%, early recognition and aggressive management can reduce the mortality to less than 5%.

Complications of acute meningococcemia include pericarditis/myocarditis, disseminated intravascular coagulation (DIC), meningitis and permanent neurologic sequelae, septic arthritis, osteomyelitis, adrenal hemorrhage (Waterhouse-Friderichsen syndrome), gangrene, and death.

Risk factors for meningococcal disease include viral infections, smoke exposure, crowded living conditions, underlying chronic diseases, and low socioeconomic status. Infants with primary or acquired deficiencies of terminal complement components or asplenia are also at increased risk of meningococcal disease.

Related topic: Chronic Meningococcemia