Infectious mononucleosis (also known as EBV infectious mononucleosis or Pfeiffer's disease or Filatov's disease and colloquially as kissing disease—from its oral transmission—or as mono in North America and as glandular fever in other English-speaking countries) is an infectious, very widespread viral disease caused by the Epstein-Barr virus (EBV), a type of Herpes virus, which well over 90% of all adults are exposed to at some point in their life