Cytomegalovirus is probably spread through the body in lymphocytes or mononuclear cells to the lungs, liver, and central nervous system where it often produces inflammatory reactions. In most patients, the disease usually runs a benign, self-limiting course. However, immunodeficient patients and those receiving immunosuppressives may develop pneumonia or other secondary infections. It primarily affects young adults and children, although in children it is usually so mild that it is often overlooked. Characteristically, infectious mononucleosis produces fever, sore throat, and cervical lymphadenopathy , as well as hepatic dysfunction, increase lymphocytes and monocytes, and development of heterophil antibodies.
Prognosis is excellent, and major complications are uncommon.
Infectious mononucleosis is fairly common and both sexes are affected equally. Symptoms of mononucleosis mimic those of other infectious diseases, including hepatitis, rubella, and toxoplasmosis. Symptoms usually subside about 6 to 10 days after onset of the disease but may persist for weeks.