Herpes simplex
Description
An in-depth report on the causes, diagnosis, treatment, and prevention of herpes simplex.
Alternative Names
Genital herpes; Fever blisters; Cold sores
Risk Factors
Everyone is at risk for herpes simplex virus. According to the latest U.S. data from 1999 - 2004, 57.7% of Americans ages 14 – 49 years are infected with the HSV-1 virus, the main cause of oral herpes and some cases of genital herpes. About 17% of Americans in the same age range test positive for the HSV-2 virus, the main cause of genital herpes. Infection rates for both viruses have declined since the late 1980s. However, infection is lifelong, so once a person is infected, he or she remains infected.
Individuals at Risk for Oral Herpes
Oral herpes is usually caused by HSV-1, which is easily transmitted and is the most common form of the herpes simplex virus. Most people with HSV-1 infection were first infected during childhood, with the highest incidence of first infection occurring between 6 months and 3 years of age. The incidence in children varies among regions and countries, with the highest rates occurring in crowded and unsanitary regions. Studies suggest that by age 5 more than a third of children in low-income areas are infected compared to 20% of children in middle-income areas. However, by the time this more privileged group reaches their thirties, about 60% have become infected with HSV-1. After age 40, socioeconomic differences in infection rates become even less pronounced.
Individuals at Risk for Genital Herpes
The number of Americans with genital herpes increased by 30% from the late 1970s through the early 1990s. However, recent surveys indicate that prevalence is decreasing. A 2006 study in the
Journal of the American Medical Association
found that among Americans ages 14 - 49 years, the prevalence of HSV-2 (the main cause of genital herpes) decreased by 19% from 1988 - 2004. The decrease was greatest among adolescents between the ages of 14 - 19.
The prevalence of HSV-1 (the main cause of oral herpes) also declined, but the percentage of genital herpes infections caused by HSV-1 more than tripled. Among people infected with HSV-1, but not HSV-2, 1.8% were diagnosed with genital herpes in 1999 -- 2004 compared with 0.4% in 1988 -- 1994. (HSV-2 still causes the majority of genital herpes infections.)
Although the prevalence of genital herpes is declining in the United States, it still remains in epidemic proportions. According to the U.S. Centers for Disease Control and Prevention (CDC), at least 45 million Americans ages 12 and over have had genital herpes. About 1 in 5 adolescents and adults are infected with genital herpes.
Genital herpes is most commonly spread by genital-to-genital or oral-to-genital contact during the days preceding an outbreak (the prodrome period).
Gender.
Anyone who is sexually active is at risk for genital herpes, and it is on the rise. Studies indicate that around 22% of Americans are infected with HSV-2, with the risk higher in women (26%) than in men (18%). Men, however, have twice as many recurrent infections as women.
Women have an 80 - 90% chance of contracting HSV-2 after unprotected sexual activity with an infected partner and are 4 times more likely to be infected than men. In one study of sexually active American adolescents, 15% of the females had evidence of being infected with HSV-2, compared to none of the males. Having a drinking problem greatly increased the likelihood of infection in these young women.
Ethnicity.
Although African Americans are more likely to test positively for HSV-2, Caucasians have a higher risk for active genital symptoms, and over the past few years the greatest increase in HSV-2 has been observed in white adolescents.
Compromised Immune Systems.
People with compromised immune systems, notably patients with HIV, the virus that causes AIDS, are at very high risk for HSV-2. Between 68 - 81% of patients with HIV are infected with HSV-2. Such patients are also at risk for more severe complications from herpes. Other immunocompromised patients include those taking drugs that suppress the immune system and transplant patients.
Individuals at Risk for Specific Forms of Herpes
The following are examples of groups that are at particularly risk for specific forms of herpes.
-
Health care providers, including doctors, nurses, and dentists. This group is at higher than average risk for herpetic whitlow, which is herpes that occurs in the fingers.
-
Wrestlers, rugby players, and other athletes who participate in direct contact sports without protective clothing. These individuals are at risk for herpes gladiatorum, an unusual form of HSV-1 that is spread by skin contact with exposed herpes sores and usually affects the head or eyes.
-
Review Date: 10/1/2006
-
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital
|
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's
accreditation program
is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s
editorial process
. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).
|
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997-2007
A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
