The effect of treating sexually transmitted diseases on the transmission of HIV in dually infected persons - A clinic-based estimate

Background: The effect of sexually transmitted disease (STD) treatment on H IV transmission is a topic of considerable current interest and controversy , Goal: To assess the potential effect of STD treatment on HIV transmission i n persons who are dually infected with STD and HIV. Study Design: Using data from eight STD clinic sites in the United States, the authors estimate the actual achievable reduction in HIV transmission by multiplying the prevented fraction associated with treatment of STDs (set at an average of 0.8) by the maximum potential reduction in HIV transmissio n achieved by treating STDs (using an average relative risk of 3.0 for incr eased HIV transmission in the presence of STDs), Subgroup analysis assessed infection proportions for genital ulcer disease, nonulcerative STDs, and a ny STD by sex, ethnicity, age, and sexual orientation. Results: The maximum achievable reduction in HIV transmission from dually i nfected persons to their partners is approximately 33%, The actual achievab le reduction is approximately 27% (range, 10.0-38.1%) at the eight clinic s ites, If each of the 4,516 dually infected persons in this cohort experienc ed a single sexual exposure with an uninfected person, 28 HIV infections wo uld occur in the absence of STD treatment whereas 16 infections would occur with STD treatment. Conclusions: The estimate of a 27% reduction provides a qualitative assessm ent of the potential impact of STD treatment on HIV transmission in the abs ence of any other behavioral intervention. Identification of dually infecte d persons in STD clinics is an important mechanism for targeting interventi ons to a social milieu with high risk for HIV infection and other STDs.