Meningococcal disease is a bacterial infection caused by Neisseria meningitis. It is the inflammation of the membranes covering the brain and spinal cord. Meningitis can produce symptoms ranging from fever and headache to deafness, strokes, brain damage or in extreme cases, death. The causes of meningitis include viruses and bacteria. Meningitis has a high mortality rate and so it is classified as a serious medical emergency. More information on viral meningitis can be found at The Centers for Disease Control and Prevention: Viral Meningitis.