What causes viral meningitis?

Many different viruses can cause meningitis. About 90% of cases of viral meningitis are caused by members of a group of viruses known as enteroviruses, such as coxsackieviruses and echoviruses. These viruses are more common during summer and fall months. Herpesviruses and the mumps virus can also cause viral meningitis.


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 infection are left with permanent neurological impairments, such as hearing loss or learning disabilities.