 Kissing on the lips can result in the transmission of some diseases, including infectious mononucleosis (known as the "kissing disease") and herpes simplex when the infectious viruses are present in saliva.Research indicates that contraction of HIV via kissing is extremely unlikely, although there was a documented case in 1997 of an HIV infection by kissing.Both the woman and infected man had gum disease, so transmission was through the man's blood, not through saliva.