Neisseria meningitidis, often referred to as meningococcus, is a bacterium that can cause meningitis and other forms of meningococcal disease such as meningococcemia, a life threatening sepsis.
Neisseria meningitidis is a major cause of morbidity and mortality during childhood in industrialized countries and has been responsible for epidemics in Africa and in Asia.
Neisseria meningitidis (Wikipedia)