With aseptic meningitis, a person has signs and symptoms of meningitis but bacteria do not grow in culture. Many different things can cause aseptic meningitis, including viruses, fungi, tuberculosis, some medications, and infections near the brain or spinal cord, such as epidural abscesses. Coxsackie virus and echovirus, two members of a family of viruses called enteroviruses, account for about half the cases of aseptic meningitis. Other enteroviruses and mumps are additional causes. The incidence of these enteroviral infections increases in the summer and early fall. West Nile virus is a cause of aseptic meningitis that has recently spread across the United States. Usually, West Nile virus causes a self-limited meningitis. Infrequently, it causes a more severe illness, which may include encephalitis or paralysis similar to that seen in polio. These severe forms usually occur in elderly people or people with compromised immune systems. Enteroviruses are spread by hand-to-mouth contact, coughing, and to a lesser extent by contact with fecal matter. Mumps is spread by coughing or contact with secretions from the mouth and airway, with increased incidence in the spring.
Herpesvirus, both type 1 (herpes simplex or herpes labialis) and type 2 (genital herpes) can cause meningitis in children and especially infants. Chicken pox can also cause aseptic meningitis. Rabies virus causes both an inflammation of the brain and meninges or a meningoencephalitis. HIV can cause aseptic meningitis, especially soon after exposure (acute HIV syndrome). Some fungi and mycobacteria can cause aseptic meningitis, although this is much less common. Certain medications can also cause aseptic meningitis, including antibiotics and some over-the-counter anti-inflammatory medications. Risk factors for aseptic meningitis include exposure to someone with recent virus infection, exposure to children in a day care setting, being a health care worker, or having a suppressed immune system .
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