How long is someone with mononucleosis contagious?

People infected with the Epstein-Barr virus, or EBV, that causes mononucleosis can pass the virus on to others for weeks or months after an initial infection, according to WebMD. Moreover, people with EBV may experience a reactivation of the virus later on in life and pass it on to others.

It takes from four to six weeks for infected people to experience symptoms of EBV after infection, notes WebMD. EBV, found in saliva, mucus and tears, lives in the throat and nose. It spreads through contact with infected fluids, usually through sharing of saliva, intimate contact, or sharing eating utensils or drinking glasses.