Definition
Viral meningitis is inflammation of the meninges. The meninges is the membrane covering the brain and spinal cord. Viral meningitis is cause by a virus. It is usually much less serious than bacterial meningitis .
Causes
A number of viruses can cause viral meningitis. These include:
- Enteroviruses
- Herpes viruses
- Mumps
- Varicella virus ( chickenpox )
- Measles
- Rubella viruses
Most of these viruses are capable of causing encephalitis . This is an inflammation of the brain tissue and 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) are spread though close personal contact or (in some cases) through the air.
- Some viruses that cause encephalitis are spread by insects.
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition. 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, and perform a physical exam with emphasis on the nervous system. An MRI or CT scan may be done to rule out other causes of the inflammation, such as a tumor.
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 culturesblood, 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.
If encephalitis is present, intravenous antiviral drugs and other medications may be given.
Antibiotics may sometimes be given for 2 to 3 days while waiting for bacterial cultures to be reported as negative.
Prevention
Prevention includes:
If you are in close contact with an infected person, wash your hands frequently.
If changing the diaper of an infected infant, wash hands immediately afterwards.
If you work in a childcare setting, regularly wash objects and surfaces handled by children with 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 mosquito populations near your home and use precautions to avoid being bitten by mosquitoes.
Avoiding viral meningitis is particularly important during pregnancy. If you are contemplating a pregnancy:
Be sure you are protected from common diseases including 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/index_e.html
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 2008 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.
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