About One-Fifth Of All People Ages 12 And Up In The U.S. Are Infected With The HSV-2 Virus That Causes Genital Herpes, But As Many As 90% Don't Know It. There Are Two Types Of Genital Herpes Type 1 (HSV-1) & Type 2 (HSV-2) Type 1 (HSV-1) Usually Causes Oral Herpes, An Infection Of The Lips & Mouth. HSV-1 Is Usually Passed From Person To Person By Kissing. HSV-1 Can Also Spread From The Mouth To The Genitals During Oral Sex