Herpes simplex, often known simply as herpes, is a viral infection caused by the herpes simplex virus. [5] Herpes infections are categorized by the area of the body that is infected. · An estimated 520 million people aged 15–49 (13%) worldwide have herpes simplex virus type 2 (HSV-2) infection, the main cause of genital herpes. Most HSV infections are asymptomatic or … · The herpes simplex virus, also known as HSV, is a viral infection that causes genital and oral herpes. Get the details on key signs, diagnosis, and treatment.