Overview of Herpes Simplex Viruses

Herpes simplex viruses HSV-1 and HSV-2 cause outbreaks on the skin and mucous membranes. After the initial infection, the virus travels to a nerve cell and becomes dormant. When reactivated by ultraviolet light, emotional stress, surgery, trauma, or hormone level fluctuation, the virus reproduces and travels down the nerve to the skin, where it produces recurring infections.

Transmission of Herpes Simplex Viruses

Contact with open sores may result in infection to others. Some infected individuals shed herpesvirus from affected areas, even when no active lesion is present.

Both HSV-1 and HSV-2 are associated with oral-facial herpes (i.e., cold sores or fever blisters) and genital herpes.

Incidence and Prevalence of Herpes Simplex Infection

Approximately one-third of the U.S. population is afflicted by cold sores and over three-fourths have been exposed to HSV-1. About 15 percent of the U.S. population aged 15-75 have been exposed to HSV-2.

Causes of Herpes Simplex Infection

Primary infection is caused by direct contact (usually sexual) with an infected individual. Signs of infection usually appear within 2 weeks of exposure. While the virus can persist on surfaces such as towels or toilet seats for as long as 60 minutes, it is extremely unusual for an infection to result from contact with these surfaces.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 31 Aug 2000

Last Modified: 21 Sep 2015