Caused by a common virus called herpes simplex (HSV-1), cold sores are contagious and can spread from person to person through skin-to-skin contact or by sharing items (such as eating utensils, lip balm, towels, cosmetics, and food), even when they aren't visible.
Infectious mononucleosis, or mono, refers to a group of symptoms usually caused by the Epstein-Barr virus (EBV). It typically occurs in teenagers, but you can get it at any age. People with mono often have a high fever, swollen lymph glands, and a sore throat.
Rarely, however, mononucleosis symptoms may recur months or even years later. Most cases of mononucleosis are caused by infection with the Epstein-Barr virus (EBV). Once you're infected with EBV, you carry the virus â usually in a dormant state â for the rest of your life.Periodically, however, the virus may reactivate.arely, however, mononucleosis symptoms may recur months or even years later. Most cases of mononucleosis are caused by infection with the Epstein-Barr virus (EBV). Once you're infected with EBV, you carry the virus â usually in a dormant state â for the rest of your life.