Earlier studies proposed that the first evidence of human lip kissing began specifically in South Asia about 3,500 years ago. From there, it was thought to have spread to other regions, potentially expediting the spread of the herpes simplex virus in the process. Often referred to as the “kissing disease,” mono is caused by the Epstein-Barr virus (EBV) and spreads through saliva. Herpes Simplex Virus (HSV): This includes both oral herpes (HSV-1) and genital herpes (HSV-2). This includes both oral herpes (HSV-1) and genital herpes (HSV-2).