Epstein-Barr virus (EBV), also known as human herpesvirus 4, is a member of the herpes virus family. It is one of the most common human viruses. EBV is found all over the world. Most people get infected with EBV at some point in their lives. EBV spreads most commonly through bodily fluids, primarily saliva. Primary EBV infection is usually asymptomatic and for many occurs during childhood, but when it occurs in adolescence or adulthood, 30%–50% cases manifest clinically as infectious mononucleosis (IM). EBV also cause infectious mononucleosis (IM), Burkitt lymphoma (BL), nasopharyngeal carcinoma (NPC), Hodgkin’s disease, and other illnesses. Many people become infected with EBV in childhood. EBV infections in children usually do not cause symptoms, or the symptoms are not distinguishable from other mild, brief childhood illnesses.