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Mononucleosis

What is infectious mononucleosis?

Infectious mononucleosis, also known as mononucleosis, "mono," or glandular fever, is characterized by swollen lymph glands and chronic fatigue.

What causes infectious mononucleosis?

Infectious mononucleosis is either caused by the Epstein-Barr virus (EBV) or the cytomegalovirus, both of which are members of the herpes simplex virus family. Consider the following statistics:

  • In the U.S., almost 95 percent of adults between 35 and 40 years old have been infected with EBV, which is a very common virus. When children are infected with the virus, they usually do not experience any noticeable symptoms. However, uninfected adolescents and young adults who come in contact with the virus may develop infectious mononucleosis in nearly 35 to 50 percent of exposures.

  • The cytomegalovirus (CMV) is actually a group of viruses in the herpes simplex virus family that often cause cells to enlarge. Most healthy persons who become infected with CMV after birth have few, if any, symptoms and have no long-term effects on their health.

  • EBV may cause infectious mononucleosis in adolescents and young adults. However, even after the symptoms of infectious mononucleosis have disappeared, the EBV will remain dormant in the throat and blood cells during that person's lifetime. The virus can reactivate periodically, however, usually without symptoms.

What are the symptoms of infectious mononucleosis?

Mononucleosis usually lasts for one to two months. The following are the most common symptoms of mononucleosis. However, each individual may experience symptoms differently. Symptoms may include:

  • Fever

  • Swollen lymph glands in the neck, armpits, and groin

  • Constant fatigue

  • Sore throat due to tonsillitis, which often makes swallowing difficult

  • Enlarged spleen

  • Liver involvement, such as mild liver damage that can cause temporary jaundice, a yellow discoloration of the skin and eye whites due to abnormally high levels of bilirubin (bile pigmentation) in the bloodstream

Once a person has had mononucleosis, the virus remains dormant in the throat and blood cells for the rest of that person's life. Once a person has been exposed to EBV, he or she is usually not at risk for developing mononucleosis again.

The symptoms of mononucleosis may resemble other medical conditions. Always consult your child's physician for a diagnosis.

How is infectious mononucleosis diagnosed?

In addition to a complete medical history and physical examination of your child, a diagnosis of mononucleosis is usually based on reported symptoms. However, diagnosis can be confirmed with specific blood tests and other laboratory tests, including:

  • White blood cell count is not diagnostic. But, the presence of a certain kind of white blood cell is suggestive of mononucleosis

  • Heterophile antibody test or monospot test, which, if positive, indicates infectious mononucleosis

How is infectious mononucleosis spread?

Mononucleosis is often spread through contact with infected saliva from the mouth. Symptoms can take between four to six weeks to appear and usually do not last beyond four months, according to the CDC. Transmission is impossible to prevent, according to the CDC, because even symptom-free people can carry the virus in their saliva.

What is the treatment for infectious mononucleosis?

Treatment for mononucleosis may include:

  • Rest for about one month (to give the body's immune system time to destroy the virus)

  • Corticosteroids (to reduce swelling of the throat and tonsils)