January 4, 2008
Genital herpes is a sexually transmitted disease (STD) caused by the herpes simplex viruses type 1 (HSV-1) or type 2 (HSV-2). Most genital herpes is caused by HSV-2. Most individuals have no or only minimal signs or symptoms from HSV-1 or HSV-2 infection. When signs do occur, they typically appear as one or more blisters on or around the genitals or rectum. The blisters break, leaving tender ulcers (sores) that may take two to four weeks to heal the first time they occur. Typically, another outbreak can appear weeks or months after the first, but it almost always is less severe and shorter than the first outbreak. Although the infection can stay in the body indefinitely, the number of outbreaks tends to decrease over a period of years.
Results of a nationally representative study show that genital herpes infection is common in the United States. Nationwide, at least 45 million people ages 12 and older, or one out of five adolescents and adults, have had genital HSV infection. Over the past decade, the percent of Americans with genital herpes infection in the U.S. has decreased.
Genital HSV-2 infection is more common in women (approximately one out of four women) than in men (almost one out of eight). This may be due to male-to-female transmission being more likely than female-to-male transmission.
HSV-1 and HSV-2 can be found in and released from the sores that the viruses cause, but they also are released between outbreaks from skin that does not appear to have a sore. Generally, a person can only get HSV-2 infection during sexual contact with someone who has a genital HSV-2 infection. Transmission can occur from an infected partner who does not have a visible sore and may not know that he or she is infected.
HSV-1 can cause genital herpes, but it more commonly causes infections of the mouth and lips, so-called "fever blisters." HSV-1 infection of the genitals can be caused by oral-genital or genital-genital contact with a person who has HSV-1 infection. Genital HSV-1 outbreaks recur less regularly than genital HSV-2 outbreaks.
Most people infected with HSV-2 are not aware of their infection. However, if signs and symptoms occur during the first outbreak, they can be quite pronounced. The first outbreak usually occurs within two weeks after the virus is transmitted, and the sores typically heal within two to four weeks. Other signs and symptoms during the primary episode may include a second crop of sores, and flu-like symptoms, including fever and swollen glands. However, most individuals with HSV-2 infection never have sores, or they have very mild signs that they do not even notice or that they mistake for insect bites or another skin condition.
People diagnosed with a first episode of genital herpes can expect to have several (typically four or five) outbreaks (symptomatic recurrences) within a year. Over time these recurrences usually decrease in frequency. It is possible that a person becomes aware of the "first episode" years after the infection is acquired.
Genital herpes can cause recurrent painful genital sores in many adults, and herpes infection can be severe in people with suppressed immune systems. Regardless of severity of symptoms, genital herpes frequently causes psychological distress in people who know they are infected.
In addition, genital HSV can lead to potentially fatal infections in babies. It is important that women avoid contracting herpes during pregnancy because a newly acquired infection during late pregnancy poses a greater risk of transmission to the baby. If a woman has active genital herpes at delivery, a cesarean delivery is usually performed. Fortunately, infection of a baby from a woman with herpes infection is rare.
Herpes may play a role in the spread of HIV, the virus that causes AIDS. Herpes can make people more susceptible to HIV infection, and it can make HIV-infected individuals more infectious.
The signs and symptoms associated with HSV-2 can vary greatly. Health care providers can diagnose genital herpes by visual inspection if the outbreak is typical, and by taking a sample from the sore(s) and testing it in a laboratory. HSV infections can be diagnosed between outbreaks by the use of a blood test. Blood tests, which detect antibodies to HSV-1 or HSV-2 infection, can be helpful, although the results are not always clear-cut.
There is no treatment that can cure herpes, but antiviral medications can shorten and prevent outbreaks during the period of time the person takes the medication. In addition, daily suppressive therapy for symptomatic herpes can reduce transmission to partners.
The surest way to avoid transmission of sexually transmitted diseases, including genital herpes, is to abstain from sexual contact, or to be in a long-term mutually monogamous relationship with a partner who has been tested and is known to be uninfected.
Genital ulcer diseases can occur in both male and female genital areas that are covered or protected by a latex condom, as well as in areas that are not covered. Correct and consistent use of latex condoms can reduce the risk of genital herpes.Persons with herpes should abstain from sexual activity with uninfected partners when lesions or other symptoms of herpes are present. It is important to know that even if a person does not have any symptoms he or she can still infect sex partners. Sex partners of infected persons should be advised that they may become infected and they should use condoms to reduce the risk. Sex partners can seek testing to determine if they are infected with HSV. A positive HSV-2 blood test most likely indicates a genital herpes infection.
Division of STD Prevention (DSTDP)
Personal Health Inquiries and Information About STDs
CDC-INFO Contact Center
National Herpes Hotline
American Social Health Association (ASHA)
Centers for Disease Control and Prevention. Sexually Transmitted Diseases Treatment Guidelines 2006. MMWR 2006; 55(no. RR-11).
Corey L, Wald A. Genital herpes. In: Holmes KK, Sparling PF, Mardh P et al (eds). Sexually Transmitted Disease, 3rd Edition. New York: McGraw-Hill, 1999, p. 285-312.
Corey L, Wald A, Patel R et al. Once-daily valacyclovir to reduce the risk of transmission of genital herpes. New England Journal of Medicine 2004; 350:11-20.
Wald A, Langenberg AGM, Link K, et al. Effect of condoms on reducing the transmission of herpes simplex virus type 2 from men to women. JAMA 2001;285: 3100-3106.
Wald A, Link K. Risk of human immunodeficiency virus infection in herpes simplex virus infection in herpes simplex virus type 2 -- seropositive persons: A meta-analysis. J Infect Dis 2002; 185: 45-52.
Weinstock H, Berman S, Cates W. Sexually transmitted diseases among American youth: Incidence and prevalence estimates, 2000. Perspectives on Sexual and Reproductive Health 2004; 36:6-10.
Xu F, Sternberg M, Kottiri B, McQuillan G, Lee F, Nahmias A, Berman S, Markowitz L. National trends in herpes simplex virus type 1 and type 2 in the United States: Data from the National Health and Nutrition Examination Survey (NHANES). JAMA 2006; Vol 296: 964-973.
This article was provided by U.S. Centers for Disease Control and Prevention. Visit the CDC's website to find out more about their activities, publications and services.