Meningitis
Meningitis, inflammation of the meninges, the membranes that surround the brain and spinal cord . Meningitis may be caused by a physical injury, a reaction to certain drugs, or more commonly, infection by certain viruses , bacteria , fungi , or parasites . This article focuses on meningitis caused by viral or bacterial infection. The most common causes of viral meningitis are coxsackie viruses and echoviruses, although herpesviruses, the mumps virus, and many other viruses can also cause the disease. Viral meningitis is rarely fatal, and most patients recover from the disease completely. Most cases of bacterial meningitis are caused by one of three species of bacteria— Haemophilus influenzae , Streptococcus pneumoniae , and Neisseria meningitidis . Many other bacteria, including Escherichia coli and the bacteria that are responsible for tuberculosis and syphilis, can also cause the disease. Bacterial meningitis can be fatal if not treated promptly. Some children who survive the infec