Herpes simplex
The two types of herpes virus are known as  simplex virus, type 1 (HSV-1) and type 2 (HSV-2). HSV-1 usually causes infections around the mouth.  HSV-2 more commonly causes genital infections. Viruses are transmitted through body fluids, or lesions in the skin. Transmission can also occur, when there are no symptoms. Genital herpes is classified as a sexually transmitted infection. It may be spread to a baby during childbirth. Herpes outbreaks can occur, because of decreased immune function, stress, and sunlight exposure.