HPTN 073 assessed the feasibility, acceptability, and safety of pre-exposure prophylaxis (PrEP) for Black men who have sex with men (BMSM). The purpose of this analysis was to characterize the relationship between PrEP uptake and use, and incident STIs among participants enrolled in HPTN 073.
226 HIV-uninfected BMSM were enrolled in three US cities; all participants received client-centered care coordination (C4) and were offered daily oral PrEP. Participants were followed for 12 months with STI testing (rectal and urine NAAT for gonorrhea and chlamydia, RPR for syphilis) conducted at baseline, week 26 and week 52. Logistic regression was used to examine associations between STI incidence and PrEP uptake. Generalized estimating equations (GEE) evaluated associations between age, PrEP acceptance, sexual behaviors, and incident STI cases.
Baseline STI prevalence was 14.2%. Men <25 were more likely to have a baseline STI (25.3% vs. 6.7%; OR 4.39; 95% CI: 1.91, 10.11). Sixty participants (26.5%) acquired ≥1 STI during follow-up; the incidence rate was 34.2 cases per 100 person-years (95% CI: 27.4, 42.9). In adjusted analyses, baseline STI diagnosis (OR 4.23, 95% CI: 1.82, 9.87; p<0.001) and additional C4 time (OR 1.03, 95% CI: 1.00, 1.06; p=0.027) were associated with having an incident STI. STI incidence was not associated with PrEP acceptance or adherence.
While we found higher rates of STIs in younger BMSM, the overall rates of STI in this trial were lower than in prior PrEP trials with no increase over time. BMSM with STIs at PrEP initiation may require additional interventions targeting STI acquisition risk.