People who are dually infected with HIV and HSV-2 may also be especially likely to transmit the HIV virus to others during genital herpes flare-ups.

"If you come into contact with the HIV virus, even after the ulcers have healed, you may be more likely to become infected," he says.

Douglas explained that the immunologic response at the site where herpes ulcers form act as a target for HIV infection even after the ulcers have disappeared.

Need for Increased Public Awareness

The reason women have higher rates of HSV-2 infection than men is largely explained by the fact that their genital tissue is more vulnerable to the small tears that make transmission more likely.

And since the background rate of infection is so high in the black community, African-American women are especially at risk, Douglas said.

"It is quite clear that this increased rate of infection in African-American women is not due to increased risk behavior," he said.

Women with HSV-2 may have no symptoms or they may mistake symptoms like genital burning and itching for a yeast infection.

The CDC does not recommend routine screening for genital herpes, but testing is recommended for those considered at high risk for getting and transmitting the virus, including people with multiple sex partners. Testing is also recommended for gay and bisexual men and people who are HIV positive.

While the infection cannot be cured, treatments that lessen the severity of genital herpes outbreaks or that may help prevent them are available.

But since most people don’t even know they have the infection, treatment rates are low, says Kevin Fenton, MD, PhD, who directs the CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention.

"Given everything we know about how to prevent, diagnose, and treat STDs, it is unacceptable that STDs remain such a widespread public health problem in the U.S. today," he says.

Douglas said collaboration between public and private-sector groups will be needed to increase public awareness about genital herpes.

He cited the "Get Yourself Tested" STD education campaign as an example. The campaign is directed at teens and young adults and is a partnership between the CDC, the television network MTV, and the philanthropic group Kaiser Family Foundation.

"Public programs alone won’t be able to get the job done, particularly in light of the increasingly tight budgets that so many local and state health departments are facing," Douglas says. "We will need to be more creative in our collective approach to STD prevention."