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 physician.
Measurement: HIV RNA in semen and blood plasma before and after introduction 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 reduction in levels of HIV RNA in semen at 6 months was 1.65 log10 units.
Conclusions: Antiretroviral therapy reduces shedding of HIV in semen, which probably in turn reduces HIV transmissibility. However, a substantial proportion of patients may still be infectious and may have drug-resistant strains of the virus.