About 1 in 6 Americans (16.2 percent) between the ages of 14 and 49 is infected with herpes simplex virus type 2 (HSV-2), according to a national health survey released today by the Centers for Disease Control and Prevention. HSV-2 is a lifelong and incurable infection that can cause recurrent and painful genital sores.
The findings, presented at the 2010 National STD Prevention Conference, indicate that herpes remains one of the most common sexually transmitted diseases (STDs) in the United States.
The new estimate, for 2005-2008, comes from CDC's National Health and Nutrition Examination Survey (NHANES), a nationally representative survey of the U.S. household population that assesses a broad range of health issues.
The findings suggest relatively stable HSV-2 prevalence since CDC's last national estimate (17 percent for 1999-2004), because the slight decline in prevalence between the two time periods is not statistically significant.
The study finds that women and blacks were most likely to be infected. HSV-2 prevalence was nearly twice as high among women (20.9 percent) than men (11.5 percent), and was more than three times higher among blacks (39.2 percent) than whites (12.3 percent). The most affected group was black women, with a prevalence rate of 48 percent.
As with other STDs, biological factors may make women more susceptible to HSV-2 infection. Additionally, racial disparities in HSV-2 infection are likely perpetuated because of the higher prevalence of infection within African-American communities, placing African-Americans at greater risk of being exposed to herpes with any given sexual encounter.
"This study serves as a stark reminder that herpes remains a common and serious health threat in the United States. Everyone should be aware of the symptoms, risk factors, and steps that can be taken to prevent the spread of this lifelong and incurable infection," said Kevin Fenton, MD, director of CDC's National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention. "We are particularly concerned about persistent high rates of herpes among African-Americans, which is likely contributing to disproportionate rates of HIV in the black community."
Research shows that people with herpes are two to three times more likely to acquire HIV, and that herpes can also make HIV-infected individuals more likely to transmit HIV to others. The CDC estimates that over 80 percent of those with HSV-2 are unaware of their infection. Symptoms may be absent, mild, or mistaken for another condition. And people with HSV-2 can transmit the virus even when they have no visible sores or other symptoms.
"Many individuals are transmitting herpes to others without even knowing it," said John M. Douglas, Jr., MD, director of CDC's Division of STD Prevention. "We can't afford to be complacent about this disease. It is important that persons with symptoms suggestive of herpes -- especially recurrent sores in the genital area -- seek clinical care to determine if these symptoms may be due to herpes and might benefit from treatment."
Although HSV-2 infection is not curable, there are effective medications available to treat symptoms and prevent outbreaks. Those with known herpes infection should avoid sex when herpes symptoms or sores are present and understand that HSV-2 can still be transmitted when sores are not present. Effective strategies to reduce the risk of HSV-2 infection include abstaining from sexual contact, using condoms consistently and correctly, and limiting the number of sex partners.
The CDC does not recommend HSV-2 screening for the general population. However, such testing may be useful for individuals who are unsure of their status and at high risk for the disease, including those with multiple sex partners, those who are HIV-positive, and gay and bisexual men.