Infectious mononucleosis(mono) is an infectious disease characterized by fever, lymphadenopathia and throat sore, spleen and liver enlargement and appearance of atypical mononuclear cells in the blood. This disease is registered in all regions. Infectious agent is Epstein-Barr pathogen virus of the herpes virus family. The source of infection is a sick person or a virus carrier. About 20% of healthy people and 100% of patients with HIV infection shed the virus. The infectious agent is allocated in saliva and transmitted by airborne droplets, kissing and sometimes sexually. Infection transmission is facilitated by overcrowding, use of common utensils, bedding, towels etc. Teenagers and people younger than 30 years old are suffered from this disease most frequently. In most cases disease results in asymptomatic infection and the formation of immunity. The virus lives in the body during the whole life.