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.
The liver or spleen may also become swollen. In less than one percent of cases splenic rupture may occur. Infectious mononucleosis is usually caused by EpsteinâBarr virus (EBV), also known as human herpesvirus 4, which is a member of the herpes virus family. A few other viruses may also cause the disease. It is primarily spread through saliva but can rarely be spread through semen or blood.