Streptococcus pneumonias and Staphylococcus are other common causes of bacterial meningitis. These organisms are widespread in the environment and it is not fully understood why some people get sick while others do not. Meningitis caused by these organisms is not contagious. Enteroviruses account for most meningitis cases for which a cause can be found. There are more than 80 different kinds of enteroviruses, but it is not clear how many of them cause meningitis.
Many enteroviral infections produce no symptoms, while others cause only mild diarrhea or vomiting.
The number of cases of viral meningitis in Massachusetts increases during late summer and early fall. People with bacterial meningitis are usually hospitalized and treated with antibiotics. There are few antiviral drugs available, but viral meningitis cases are usually self-limited to ten days or less. A vaccine to prevent H. influenzae type b meningitis is available and recommended for all children between 18 months and five years old. The vaccine can prevent meningitis, but it is useless as a treatment once meningitis has developed.