What Causes Meningococcal Meningitis? Bacteria and viruses are the two main causes of meningitis. The bacterium Neisseria meningitidis, also called meningococcus, causes meningococcal meningitis. In children and teens, meningococcus is the most common cause of bacterial meningitis. In adults, it is the second most common cause.
Meningitis can be caused by: bacteria; fungi; viruses ; parasites; Most forms of meningitis are caused by viruses. Pneumococcal meningitis, however, is a bacterial form of meningitis. It’s a serious disease that can cause death even with proper treatment. See your doctor right away if you suspect you may have pneumococcal meningitis.