Infectious mononucleosis originates from the Epstein-Barr virus in the herpes virus category, which two researchers identified in 1964, although the disease had been recognized many years before, according to WebMD. Patients spread the Epstein-Barr virus through contact with infected saliva, causing mononucleosis to be called the kissing disease.
Mononucleosis symptoms include headache, fever, sore throat, swollen neck glands and fatigue. A person is able to live in close quarters with someone who has mononucleosis and not contract the illness. However, the virus remains active months after a patient's symptoms disappear, which poses a continuing risk to others, notes WebMD. Having a strong immune system helps protect against the infection.