The two most common invasive meningococcal diseases are meningitis and a blood stream infection called meningococcemia.
Infections commonly occur in previously healthy persons.
Meningococcal infections can be very serious and have a mortality rate of one in every seven infected. In addition, permanent sequelae develop in a small percent of survivors. At present, bacterial meningitis is epidemic on the Indian subcontinent and in much of sub Saharan Africa.