Meningitis

Definition

Meningitis is a bacterial infection of the membranes covering the brain and spinal cord (meninges).

Causes

The most common causes of meningitis are viral infections that usually get better without treatment. However, bacterial meningitis infections are extremely serious, and may result in death or brain damage, even if treated.

Meningitis may also be caused by:

Most viral meningitis is due to enteroviruses, which are viruses that also can cause intestinal illness.

Many other types of viruses can cause meningitis. 

Symptoms

Viral meningitis occurs more often than bacterial meningitis, and is milder. It usually occurs in the late summer and early fall. It most often affects children and adults under age 30. 

Bacteria meningitis is an emergency. You will need immediate treatment in a hospital. Symptoms usually come on quickly, and may include:

Other symptoms that can occur with this disease:

Meningitis is an important cause of fever in children and newborns.

You cannot tell if you have bacterial or viral meningitis by how they feel. Your health care provider must do this. Seek prompt attention if you have symptoms of meningitis. 

Exams and Tests

The doctor or nurse will examine you. This may show:

If the health care provider thinks you have meningitis, a lumbar puncture (spinal tap) should be done to remove a sample of spinal fluid (cerebrospinal fluid, or CSF) for testing.

Other tests that may be done include:

Treatment

Antibiotics are used to treat bacterial meningitis. The specific type depends on which bacteria is causing the infection. Antibiotics do not treat viral meningitis.

Antiviral medicine may be given to those with herpes meningitis.

Other treatments will include:

Outlook (Prognosis)

Early diagnosis and treatment of bacterial meningitis is essential to prevent permanent neurological damage. Viral meningitis is usually not serious, and symptoms should disappear within 2 weeks with no lasting complications.

Possible Complications

When to Contact a Medical Professional

If you think that you or your child has symptoms of meningitis, get emergency medical help immediately. Early treatment is key to a good outcome.

Prevention

Certain vaccines can help prevent some types of meningitis.

Household members and others in close contact with people who have meningococcal meningitis should receive antibiotics to prevent becoming infected.

The meningococcal vaccination is recommended for:

Some communities hold vaccination campaigns after an outbreak of meningococcal meningitis.


Review Date: 10/6/2012
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.

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