Meningitis is an illness in which there is inflammation of the tissues that cover the brain and spinal cord. Viral or "aseptic" meningitis, which is the most common type, is caused by an infection with one of several types of viruses. Meningitis can also be caused by infections with several types of bacteria or fungi. In the United States, there are between 25,000 and 50,000 hospitalizations due to viral meningitis each year.

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.

Is viral meningitis a serious disease?

Viral ("aseptic") meningitis is serious but rarely fatal in persons with normal immune systems. Usually, the symptoms last from 7 to 10 days and the patient recovers completely. Bacterial meningitis, on the other hand, can be very serious and result in disability or death if not treated promptly. Often, the symptoms of viral meningitis and bacterial meningitis are the same. For this reason, if you think you or your child has meningitis, see your doctor as soon as possible.

Risk Factors

Enteroviruses, the most common cause of viral meningitis, are most often spread through direct contact with respiratory secretions (e.g., saliva, sputum, or nasal mucus) of an infected person. This usually happens by shaking hands with an infected person or touching something they have handled, and then rubbing your own nose or mouth. The virus can also be found in the stool of persons who are infected. The virus is spread through this route mainly among small children who are not yet toilet trained. It can also be spread this way to adults changing the diapers of an infected infant. The incubation period for enteroviruses is usually between 3 and 7 days from the time you are infected until you develop symptoms. You can usually spread the virus to someone else beginning about 3 days after you are infected until about 10 days after you develop symptoms.

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 Cultures–blood, urine, mucous, and/or pus from skin infections

Can I get viral meningitis if I’m around someone who has it?

The viruses that cause viral meningitis are contagious. Enteroviruses, for example, are very common during the summer and early fall, and many people are exposed to them. However, most infected persons either have no symptoms or develop only a cold or rash with low-grade fever. Only a small proportion of infected persons actually develop meningitis. Therefore, if you are around someone who has viral meningitis, you have a moderate chance of becoming infected, but a very small chance of developing meningitis.

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 (corticosteroids) may be given.

• Antibiotics may sometimes be given for 2-3 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

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