Genital herpes

Genital herpes is a sexually transmitted viral infection that is characterized by repeated eruptions of small, painful blisters on the genitals, around the rectum, or covering adjacent areas of skin.

Herpes - genital; Herpes simplex - genital; Herpesvirus 2; HSV-2

Herpes is caused by two viruses -- herpes simplex virus type 1 (HSV-1), and herpes simplex virus type 2 (HSV-2). While statistics vary, research shows that 90% of the population has been exposed to HSV-1, "oral herpes," and 25% of the population aged 25-45 years old in the United States has been exposed to infection with HSV-2, "genital herpes."

HSV-1, the virus responsible for common cold sores, can be transmitted through oral secretions. This usually occurs during kissing, or by eating and drinking from contaminated utensils.

Additionally, HSV-1 can cause genital herpes through transmission during oral-genital sex, thus both strains of the virus may be transmitted by sexual contact. Initial oral herpes infection, however, usually occurs in childhood. It is therefore not classified as a sexually transmitted disease.

HSV-1 is responsible for only 5-10% of genital herpes cases, while HSV-2 causes the majority of genital herpes cases. HSV-2 can be transmitted through oral or genital secretions. An estimated 86 million people worldwide are thought to have genital herpes.

Because the virus is transmitted through secretions from the oral or genital mucosa (skin), common sites of infection in men include the shaft and head of the penis, the scrotum, inner thighs, and anus. The labia, vagina, cervix, anus, and inner thighs are common sites in women. The mouth can also be a site of infection in both sexes.

Research suggests that the virus can be transmitted even when there are no symptoms present, so that a sexual partner without obvious genital herpes sores may still transmit the illness. In fact, asymptomatic spread may actually contribute more to the spread of genital herpes than do active sores.