Viral Meningitis
(Aseptic Meningitis)
Definition
The brain and spinal cord are encased by layers of tissue. These layers are called the meninges. Certain viruses can cause an infection in these layers. This is called viral meningitis.
Some types can be less serious than bacterial meningitis .
The Spinal Cord and Meninges
Causes
A number of viruses can cause viral meningitis including:
- Enteroviruses
- Herpes viruses
- Mumps
- Varicella virus ( chickenpox )
- Measles
- Rubella viruses
- West Nile virus
Most of these are also able to cause encephalitis . This is an inflammation of the brain tissue. It is a much more serious condition.
Viruses that cause meningitis can be spread in numerous ways:
-
Enteroviruses are spread:
- Via direct contact with respiratory secretions of an infected person
- Through feces
- Other viruses (mumps, herpes, chickenpox) spread though close personal contact or through the air
- Some viruses (West Nile) that cause encephalitis are spread by insects
Risk Factors
Risk factors for viral meningitis include:
- Conditions that weaken the immune system, such as HIV infection (which itself can lead to meningitis/encephalitis)
- Immunosuppressive treatments
- Crowded, unsanitary conditions
- Season: summer and early fall
Symptoms
Classic symptoms of viral meningitis include:
- High fever
- Headache
- Stiff, sore neck
- Nausea
- Vomiting
- Sensitivity to bright lights
- Sleepiness
In newborns and infants:
- Inactivity
- High fever (especially unexplained high fever)
- Irritability
- Vomiting
- Feeding poorly or refusing to eat
- Tautness or bulging of soft spots between skull bones
- Difficulty awakening
Diagnosis
The doctor will ask about your symptoms and medical history. A physical exam will be done. The doctor will focus on the nervous system. To help rule out other causes of the inflammation, such as a tumor, your doctor may order an:
- MRI scan —a test that uses magnetic waves to make pictures of structures inside of the body
- CT scan —a type of x-ray that uses a computer to make pictures of structures inside of the body
To rule out bacterial meningitis, the following tests may be done:
- Lumbar puncture (spinal tap) —removal of fluid from the lower spinal column to be tested for bacteria (bacterial cultures)
- Other cultures—blood, urine, mucus, and/or pus from skin infections
Treatment
Treatment includes:
- Rest and fluids
- Nonsteroidal anti-inflammatory drugs
- Aspirin
—Note: Aspirin is not recommended for children with a current or recent viral infection
- Check with your doctor before giving a child aspirin
- Antibiotics may be given for 2 to 3 days while waiting for bacterial cultures to be reported as negative
- IV antiviral drugs and other medications may be given
If you are diagnosed with viral meningitis, follow your doctor's instructions .
Prevention
Wash your hands often particularly:
- If you are in close contact with an infected person
- Immediately after changing the diaper of an infected infant
If you work in a childcare setting:
- Regularly wash objects and surfaces touched by children
- Use a diluted bleach solution
If you've never had measles, mumps, rubella, and chickenpox:
- Consider being vaccinated
Some forms of viral meningitis are spread by mosquito bites:
- Follow public health recommendations for reducing mosquitoes near your home
- Take steps to avoid being bitten by mosquitoes
If you are contemplating a pregnancy:
- Be sure you are protected from common diseases (eg, chickenpox)
-
Avoid all contact with rodents during pregnancy:
- Lymphocytic choriomeningitis virus can be acquired from pet hamsters, mice, or other rodents
- If you own a rodent, consider finding another home for it while you are pregnant
RESOURCES:
Meningitis Foundation of America
http://www.musa.org/
US Centers for Disease Control and Prevention
http://www.cdc.gov/
CANADIAN RESOURCES:
Health Canada
http://www.hc-sc.gc.ca/
Public Health Agency of Canada
http://www.phac-aspc.gc.ca/
References:
The Merck Manual of Medical Information . 18th ed. Merck; 2006.
The Merck Manual of Medical Information . 17th ed. Simon and Schuster, Inc.; 2000.
National Center for Infectious Diseases website. Available at: http://www.cdc.gov/ncidod/ .
US Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov .
Last reviewed January 2009 by David L. Horn, MD, FACP
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © 2007 EBSCO Publishing All rights reserved.