Some studies show mono to remain contagious for up to 18 months after the symptoms disappear, according to KidsHealth. While it is contagious from the time of infection, symptoms do not begin for four to seven weeks after the initial contact.
Mononucleosis spreads through the saliva of infected individuals, often through kissing or sharing a drink. Most people develop immunity through exposure to the Epstein-Barr virus as a child. Often symptoms are mild or go unnoticed. In individuals between ages 15 and 24, the virus often develops as mono. According to Brown University, there are no specific cures for the virus, but infected students should get plenty of rest, increase fluid intake and use nonprescription pain medication.