Most of the people at greater risk of acquiring HIV, the virus that leads to AIDS, don’t know it, according to an analysis by researchers at the University of Washington.
That’s because most people who have HSV-2, the virus responsible for genital herpes, are unaware of the infection that dramatically increases their risk of acquiring HIV. HSV-2 is present in 22 percent of people in the United States over the age of 12, but most are unaware of it because they are asymptomatic or do not recognize their symptoms.
There’s considerable evidence that HSV-2 infection is a risk factor for acquiring AIDS. A metanalysis of 31 studies, published in the Jan. 1 issue of the Journal of Infectious Diseases, shows that the higher risk was found in people with HSV-2 antibodies, and not necessarily the symptoms of genital herpes.
“This is important because most people with HSV-2 infection do not know they have the infection — and therefore, may be at higher risk for acquiring HIV. This may help explain why HIV has spread faster in some groups rather than others,” says Dr. Anna Wald, who collaborated on the paper with colleague Katherine Link. Wald is director of the University of Washington Virology Research Clinic and an assistant professor of allergy and infectious diseases in the UW School of Medicine and of epidemiology in the UW School of Public Health and Community Medicine.
Several studies have looked preventing HIV infection by treating people for bacterial STDs, such as chlamydia, gonorrhea, and syphilis. But these prevention measures have not held up to their promise; that may be because people are not treating HSV-2 infection, one of the most common STDs. People with HSV-2 are twice as likely to contract HIV than other people, according to the analysis.
The analysis says that between one in five and one in three cases of HIV may be attributed to the preceding HSV-2 infection. In fact, in groups where HSV-2 infection affects 80 percent of the population, such as some places in Africa, almost half of HIV cases may be attributable to HSV-2.
“Limiting our diagnostic and therapeutic efforts to bacterial STDs and excluding viral STDs may not be enough to impact HIV acquisition,” the analysis says.
“Clearly, control of HSV-2 infection should be part of the arsenal that we use to try to control HIV infection,” Wald says. She suggests that further studies be conducted to see if acyclovir, a drug used commonly to treat HSV infection, may have promise in decreasing risk of HIV infection.
However, long-term treatment of large populations with acyclovir may not be practical. The best answer would be a vaccine against HSV-2. The University of Washington has been one of the leading centers of herpes research for the last 20 years. Its Virology Research Clinic is studying several approaches to the treatment and prevention of HSV-2 infection.
People interested in participating in studies relating to HSV-2 treatment, prevention, or vaccines can call the UW Virology Research Clinic at (206) 720-4340.