Mononucleosis, Infectious

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Mononucleosis, Infectious, also glandular fever, an acute disease of humans, caused by the Epstein-Barr virus. Its mode of transmission is not known, but may be facilitated by saliva exchange, as in kissing. The disease, which attacks chiefly adolescents and young adults, usually runs its course in two to four weeks, although cases may be as brief as a week or last six to eight weeks. After recovery, weakness may continue for several months. Mononucleosis is characterized by fever, sore throat, fatigue, malaise, and loss of appetite, often associated with nausea. Patients generally have swelling of the lymph nodes in the neck and elsewhere and often have an enlarged spleen.

Examination of the blood usually shows an increase in the white blood cells, due to the appearance in the blood of many atypical lymphocytes. The blood serum in infectious mononucleosis often contains an antibody known as heterophile antibody that agglutinates, or clumps, the red blood cells of sheep. Serological tests based on this property of the patient's serum may serve to confirm the diagnosis of the disease. In addition, tests for liver function frequently show mild abnormalities. No therapeutic agent has proved effective in the treatment of mononucleosis.

See also List of human diseases caused by viruses

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