Evaluation of point-of-care diagnostics for sexually transmitted infection on oral PrEP initiation and persistence among young people in South Africa: a randomized controlled study.

INTRODUCTION

Pre-exposure prophylaxis (PrEP) services are linked to increased sexually transmitted infection (STI) diagnoses, which may facilitate PrEP uptake. We hypothesized that point-of-care (POC) STI testing and treatment would improve PrEP initiation and persistence.

METHODS

Between September 2023 and November 2024, we conducted a single-centre, open-label, unblinded, randomized controlled trial among adolescent girls and young women (15-29 years old) or male partners (any age). Participants were randomized 1:1 to standard syndromic STI management (SOC) or POC testing for C. trachomatis, N. gonorrhoeae, syphilis and T. vaginalis (women only). All participants received standard HIV prevention counselling, including the offer of oral PrEP. The primary outcome was effect of POC STI testing versus syndromic management on PrEP initiation; secondary outcomes included persistence at 1 and 4 months (PrEP prescription), verified in the secondary analysis of tenofovir diphosphate (TFV-DP) in dried blood spots (DBS) in a random subset. TFV-DP in DBS was analysed in a subset. Analysis was intention-to-treat, adjusted for age and sex.

RESULTS

We enrolled and randomized 900 participants (452 in intervention; 448 in SOC). The mean age was 20.4 years (SD = 4.2); 48% were female. In the intervention arm, 435 received POC STI testing (96%); 25% (110 of 435 tested) were diagnosed with =>1 STIs; 84% were treated. In SOC, 7% of participants reported symptoms of STIs (31); 88% were treated (27). Overall, 64% of participants in SOC versus 62% in intervention-initiated PrEP (RR = 0.98, 95% CI = 0.88ng women and partners1.08). In the intervention, 41% persisted on PrEP at 1 month and 25% through 4 months, compared to 46% and 19%, respectively, in SOC (aRR intervention = 1.39; 95% CI = 0.93-2.09; p = 0.08). In participants treated for STIs or syndromically, 77% initiated PrEP versus 60% untreated/diagnosed (aRR = 1.14; 95% CI = 1.02-1.27); 19% versus 14% persisted on PrEP at 4 months (aRR STI/syndrome treated = 1.41; 95% CI = 0.79-2.51). Overall, 30% of 64 DBS had any TFV-DP levels present with no difference by study arm (RR = 0.74; 95% CI: 0.38-1.41).

CONCLUSIONS

POC STI testing did not increase PrEP initiation or 1-month persistence but showed a moderate association with 4-month persistence. STI treatment (syndromic or confirmed) was linked to higher PrEP uptake and persistence. Integrating STI management may improve PrEP persistence among youth.