Abstract:
Antiretroviral-based interventions for HIV-1 prevention, including antiretroviral therapy (ART)
to reduce the infectiousness of HIV-1 infected persons and pre-exposure prophylaxis (PrEP)
to reduce the susceptibility of HIV-1 uninfected persons, showed high efficacy for HIV-1 protection
in randomized clinical trials. We conducted a prospective implementation study to
understand the feasibility and effectiveness of these interventions in delivery settings.
Methods and Findings
Between November 5, 2012, and January 5, 2015, we enrolled and followed 1,013 heterosexual
HIV-1-serodiscordant couples in Kenya and Uganda in a prospective implementation
study. ART and PrEP were offered through a pragmatic strategy, with ART promoted for all
couples and PrEP offered until 6 mo after ART initiation by the HIV-1 infected partner, permitting
time to achieve virologic suppression. One thousand thirteen couples were enrolled 78%of partnerships initiated ART, and 97% used PrEP, during a median follow-up of 0.9
years. Objective measures of adherence to both prevention strategies demonstrated high
use ( 85%). Given the low HIV-1 incidence observed in the study, an additional analysis
was added to compare observed incidence to incidence estimated under a simulated counterfactual
model constructed using data from a prior prospective study of HIV-1-serodiscordant
couples. Counterfactual simulations predicted 39.7 HIV-1 infections would be expected
in the population at an incidence of 5.2 per 100 person-years (95%CI 3.7–6.9). However,
only two incident HIV-1 infections were observed, at an incidence of 0.2 per 100 personyears
(95%CI 0.0–0.9, p < 0.0001 versus predicted). The use of a non-concurrent comparison
of HIV-1 incidence is a potential limitation of this approach; however, it would not have
been ethical to enroll a contemporaneous population not provided access to ART and PrEP
