What is Herpes? Herpes is a sexually transmitted infection (STI) caused by the herpes simplex virus type 1 (HSV-1) or type 2 (HSV-2). Genital herpes is generally defined as an HSV infection of the groin, pubic area, urethra (the tube that allows urine and semen to pass out of the body), vagina, vulva, cervix, clitoris, […]