Infectious mononucleosis is frequent among young adults. In the United States, approximately 50% of the population develops antibodies to the Epstein-Barr virus before the age of five; much of the rest of the population develops antibodies in adolescence or young adulthood
College-aged students are the most susceptible. Mortality and morbidity rates due to uncomplicated infectious mononucleosis are low. Death is caused by rare cases due to spontaneous splenic rupture. Other cases of mortality are due to previous underlying conditions.