Meningococcal disease is a serious infection caused by serotypes A, B, C, W-135 and Y of the bacteria, Neisseria meningitidis.
Meningococcal disease occurs throughout the year. However, the incidence is highest in the late winter and early spring. Approximately 800–1,200 cases occur annually in the United States. Most cases are sporadic; very few cases occur as part of an outbreak.
The mortality rate is approximately 10%, and 11%–19% of survivors have long-term sequelae (e.g., neurologic disability, limb or digit loss, and hearing loss).