There are two types of herpes simplex virus, type 1 more commonly causes oral infections while type 2 more commonly causes genital infections. Genital herpes is classified as a sexually transmitted infection. It may be spread to an infant during childbirth.After infection, the viruses are transported along sensory nerves to the nerve cell bodies, where they reside lifelong. Causes of recurrence may include: decreased immune function, stress, and sunlight exposure.