Infectious Mononucleosis (cont.)

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What is the cause of mono?

The EBV that causes mono is found throughout the world. By the time most people reach adulthood, an antibody against EBV can be detected in their blood. In the U.S., up to 95% of adults 35-40 years of age have antibodies directed against EBV. This means that most people, sometime in their lives, have been infected with EBV. The body's immune system produces antibodies to attack and help destroy invading viruses and bacteria. These specific antibodies can be detected in the blood of people who have been infected.

When infection occurs in childhood, the virus most often produces no symptoms. It is estimated that only about 10% of children who become infected with EBV develop the illness. Likewise, probably because of immunity from prior infection, adults typically do not develop the illness. Most cases of infectious mononucleosis occur in the 15-24 age group.

While there are other illnesses falling under the broad classification of mononucleosis that can cause similar symptoms (cytomegalovirus [CMV] infection is one example) and an increase in blood lymphocytes, the mononucleosis caused by the EBV is by far the most common.

What are the risk factors for mono?

The EBV can infect any person. As previously discussed, the majority of people have become infected with the virus by the time that they reach adulthood, and the majority of these infections produce no symptoms or are not recognized as mono. Mono is most often diagnosed in adolescents and young adults, with a peak incidence at 15-17 years of age. However, it can also be seen in children. Generally, the illness is less severe in young children and may mimic the symptoms of other common childhood illnesses, which may explain why it is less commonly diagnosed or recognized in this younger age group.

Picture of Infectious Mononucleosis Symptoms and Signs
Picture of infectious mononucleosis symptoms and signs
Medically Reviewed by a Doctor on 9/25/2013

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