causes of meningitis in adults
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. Meningococcal bacteria may cause infection in a part of the body -- the skin, gastrointestinal tract, or respiratory tract, for instance.
Meningitis is inflammation of the lining around the brain and spinal cord. It is usually caused by an infection. The infection occurs most often in children, teens, and young adults. Also at risk are older adults and people who have long-term health problems, such as a weakened immune system. There are two main kinds of meningitis: Viral meningitis is fairly common. It usually doesn't cause serious illness.