Final answer:
Genital herpes is most commonly caused by Herpes simplex virus type 2 (HSV-2), but can also be caused by Herpes simplex virus type 1 (HSV-1). Transmission occurs through sexual contact, even when there are no visible symptoms.
Step-by-step explanation:
Genital herpes is most commonly caused by Herpes simplex virus type 2 (HSV-2). Increasingly, however, genital herpes is also caused by Herpes simplex virus type 1 (HSV-1). HSV-1 more commonly causes oral herpes, while HSV-2 is more commonly associated with genital herpes infections. Transmission of genital herpes occurs through sexual contact with someone who has the virus, even when there are no visible symptoms.