Effect of antiretroviral therapy on HIV shedding in semen

Background: The effect of antiretroviral therapy on seminal HIV shedding in the community remains unknown. Objective: To evaluate the effect of antiretroviral therapy on HIV shedding in semen. Design: Prospective cohort study. Setting: University hospital in Rio de Janeiro, Brazil. Patients: 93 HIV-infected men. Intervention: Antiretroviral therapy as prescribed by each patient's physic ian. Measurement: HIV RNA in semen and blood plasma before and after introductio n of therapy. Results: At baseline, HIV RNA was detected in 69 semen samples (74%) and 89 blood samples (96%), Six months after introduction of therapy, HIV RNA was detected in 29 semen samples (33%) and 33 blood samples (38%). The mean re duction in levels of HIV RNA in semen at 6 months was 1.65 log(10) units. Conclusions: Antiretroviral therapy reduces shedding of HIV in semen, which probably in turn reduces HIV transmissibility. However, a substantial prop ortion of patients may still be infectious and may have drug-resistant stra ins of the virus.