A general term for any illness that involves inflammation of the meninges. It is frequently caused by the bacterium Neisseria meningitidis. Such meningococcal meningitis is an acute, infectious disease that causes symptoms such as skin rash, headache, congestion, neck muscle rigidity, light sensitivity, nausea and convulsions. The bacterium Listeria monocytogenes, which is found in human feces, can also cause the disease. A much less common cause of meningitis is advanced-stage syphilis. The term can also refer to the symptom of having inflamed meninges.