mononucleosis

mononucleosis A condition resulting from infection with the Epstein-Barr virus (EBV, human herpesvirus 4 [HHV-4]) in which there is an increase of white blood cells that have a single nucleus (monocytes). The infection can be spread by saliva. Its incubation period is 4 to 8 weeks. Symptoms include fever, fatigue, sore throat, and swollen lymph glands. Mononucleosis can cause liver inflammation (hepatitis) and spleen enlargement; a person with mononucleosis should avoid vigorous contact sports to prevent spleen rupture. It is less severe in young children than in others. Most people exposed to EBV do not develop mononucleosis; most adults carry an antibody against EBV in their blood, which means they have been infected with EBV at some time. Treatment includes rest, pain medication, and in some cases antiviral medication. Also known as mono and the kissing disease. See also Epstein-Barr virus.