Aseptic meningitis is an illness that appears similar to bacterial meningitis. However, bacteria do not grow in cultures of the fluid around the brain and spinal cord (cerebrospinal fluid). This may occur because there are no bacteria, or because the bacteria are difficult to grow.
- Meningitis - cryptococcal
- Meningitis - Gram-negative
- Meningitis - H. influenzae
- Meningitis - meningococcal
- Meningitis - pneumococcal
- Meningitis - staphylococcal
- Meningitis - tuberculous
Causes, incidence, and risk factors
There are many causes of aseptic meningitis, including:
- Cancer (causes a syndrome similar to meningitis)
- Infections near the brain or spinal cord, such as epidural abscesses
- Medications (cause a syndrome similar to meningitis)
- Mycobacteria (nontuberculous)
- Tick-borne diseases (such as Lyme disease)
About half of aseptic meningitis cases are caused by coxsackie virus or echovirus, two members of the enterovirus family. The rate of enteroviral infections increases in the summer and early fall. Enteroviruses are spread by hand-to-mouth contact and coughing. They also may be spread by contact with fecal matter.
Other viruses that cause this condition include:
- Chickenpox (varicella virus)
- Other enteroviruses
- Herpes simplex viruses, usually type 2
- HIV (especially acute HIV syndrome)
- Rabies virus
- West Nile virus
Risk factors for aseptic meningitis include:
- Being a health care worker
- Having a weakened immune system
- Exposure to children in a day care setting
- Exposure to someone with a recent viral infection
- Abdominal pain
- Abnormal sensitivity to light (photophobia)
- General discomfort, uneasiness, or ill feeling (malaise)
- Muscle pain
- Nausea and vomiting
- Sore throat
- Stiff neck
Signs and tests
Physical examination may show:
- Fast heart rate
- Stiff neck
For any patient who is suspected of having meningitis, it is important to perform a lumbar puncture ("spinal tap"), in which spinal fluid (known as cerebrospinal fluid, or CSF) is collected for testing.
Tests that may be done include:
- Blood culture
- Chest x-ray
- CSF examination for cell count, glucose, and protein
- CT scan of the head
- Gram stain, other special stains, and culture of CSF
- Polymerase chain reaction (PCR) of CSF
Treatment is needed for fungal or mycobacterial causes of aseptic meningitis. Herpesvirus or varicella (chickenpox) virus may be treated with antiviral medicines. Treatment for noninfectious causes consists of pain medications and managing complications, if they occur.
No specific treatment is available for enteroviral or most other viral forms of aseptic meningitis.
Unlike other forms of meningitis, aseptic meningitis caused by a virus is usually a harmless disease. Less than 1% of patients have lasting symptoms. People usually recover fully 5 - 14 days after symptoms start.
Fatigue and lightheadedness may last longer in some people.
An infection of the brain (encephalitis) may develop, though this is rare. The infection may last much longer in a person with a weakened immune system.
Calling your health care provider
Call your health care provider if you have symptoms of aseptic meningitis.
To reduce the risk of developing an infection that can become meningitis:
- Get vaccinated (against mumps or chickenpox, for example)
- Practice good hand washing
- Practice other general good health measures
Swartz MN. Meningitis: bacterial, viral, and other. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsever; 2007:chap 437.