Herpes genitalis (or genital herpes) refers to a genital infection by Herpes simplex virus. Following the classification HSV into two distinct categories of HSV-1 and HSV-2 in the 1960s, it was established that 'HSV-2 was below the waist, HSV-1 was above the waist'. Although genital herpes was previously caused primarily by HSV-2, genital HSV-1 infections are increasing and now cause up to 80% of infections. HSV is believed to be asymptomatic in the majority of cases, thus aiding contagion and hindering containment. When symptomatic, the typical manifestation of a primary HSV-1 or HSV-2 genital infection is clusters of genital sores consisting of inflamed papules and vesicles on the outer surface of the genitals, resembling cold sores. These usually appear 47 days after sexual exposure to HSV for the first time. Genital HSV-1 infection recurs at rate of about one sixth of that of genital HSV-2.