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Infectious Mononucleosis

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What is it?

Infectious mononucleosis is a common viral illness caused by Epstein-Barr virus (EBV). It occurs worldwide and is often diagnosed in the teenage and young adult population due to social behaviours of this age group. In young children the disease is usually very mild and more difficult to diagnose. By adulthood, 90 to 95% of people have been exposed to the virus and are immune.

What are the symptoms?

Symptoms of mononucleosis include sore throat, fever, swollen and tender lymph glands and enlarged spleen. The most common symptom is severe sore throat lasting three to five days which usually resolves in seven to 10 days. The onset of illness can be abrupt, but often will appear gradually over several days, with chills, sweats and loss of appetite.

How is it spread?

The virus is spread from person to person through saliva. Kissing, sharing items like eating utensils or drink containers, lipstick, cigarettes or musical instruments with mouthpieces are all common sources of spread. Transmission of this virus through air or blood does not normally occur. Symptoms appear four to six weeks after contact with the virus. People with mononucleosis may be able to spread the virus to others for a prolonged period of time. However since the virus is also frequently found in the saliva of healthy people, no special precautions are recommended. Many healthy people carry this virus throughout their lifetimes without even knowing it. Therefore, spread of infectious mononucleosis is almost impossible to prevent.

Recommended absence

A person may return to school or work when he or she is feeling well enough to participate in normal activities without tiring. This varies from case to case, depending on the severity of the illness. Rest is an important part of recovery. Too early a return to activities may result in a prolonged recovery time.

For more information, please contact a member of Haldimand-Norfolk Health Unit’s Infectious Disease Team.
Simcoe Office: 519.426.6170 / 905.318.6623
Caledonia Office: 905.318.5367