Mono is short for mononucleosis, and it is a viral infection. It is an illness most commonly caused by infection from the Epstein-Barr Virus, although other viruses can be the source as well. Mono is also known as “the kissing disease." It’s transmitted through contact with infected bodily fluids, including saliva. Mono has some symptoms that may seem like allergies or strep throat, but it is not the same thing. It is important to ...