SAN FRANCISCO — The use of acyclovir to suppress herpes simplex virus or to prevent herpes transmission failed to reduce transmission of HIV in several recent international studies.
Previous data have shown that type 2 herpes simplex virus (HSV-2) infection increases the risk for HIV acquisition and transmission. Investigators had hoped that medical suppression of HSV-2 reactivation might reduce HIV transmission rates in areas such as Africa, which has a very high (90%) seroprevalence of HSV, Dr. Diane V. Havlir said. The data, however, showed that HSV-2 suppression had no effect on HIV. “This particular strategy has been put on hold,” she said at a meeting on the medical management of HIV and AIDS sponsored by the University of California, San Francisco.
A 2008 study randomized 3,172 HIV-negative, HSV-2 seropositive patients in Africa, Peru, and the United States to 800 mg acyclovir or matching placebo for 12–18 months (Lancet 2008;371:2109–19). Although acyclovir reduced the likelihood of developing genital ulcers compared with placebo, the incidence of HIV acquisition was similar between groups (3.9 and 3.3 cases per 100 person-years, respectively), noted Dr. Havlir, professor of medicine at the university and chief of the HIV/AIDS division at San Francisco General Hospital.
Some of the same investigators reported separate unpublished data at the 2009 International AIDS Society meeting in Cape Town, South Africa, showing similarly disappointing results in a study of 3,408 serodiscordant couples, Dr. Havlir added. She reported having no conflicts of interest related to these topics.