Correlates of self-reported and biomarker based adherence to daily oral HIV pre-exposure prophylaxis among a cohort of predominantly men who have sex with men in Nigeria

Risk Compensation After Initiation of Daily Oral Pre-exposure Prophylaxis Among Sexual and Gender Minorities in Nigeria

Pre-exposure prophylaxis (PrEP) use may be associated with risk compensation. We enrolled and provided PreP to sexual and gender minorities (SGM) in Abuja, Nigeria between April 2018 and May 2019. Behavioral information and samples for urogenital and anorectal Chlamydia trachomatis and Neisseria gonorrhoeae sexually transmitted infections (STIs) were collected at baseline. Blood samples for PrEP assay and self-reported adherence were collected at three-monthly follow-up visits. STIs were detected using Aptima Combo2 assay. We estimated the odds ratios (ORs) of PCR-diagnosed bacterial STIs and self-reported behavioral outcomes (condomless anal intercourse [CAI] and concurrent sexual relationships) with conditional logistic regression. Of 400 SGM who initiated PrEP, 206 were eligible for analysis, and had a median age of 24 years (IQR 22-27). In multivariable analysis, participants in the PrEP period had decreased odds of CAI (adjusted OR: 0.49, 95% CI 0.28, 0.84). PrEP use was not associated with risk compensation.

Low daily oral PrEP adherence and low validity of self-report in a randomized trial among PWID in Ukraine

BACKGROUND

The efficacy of daily oral pre-exposure prophylaxis (PrEP) in preventing HIV transmission among people who inject drugs (PWID) was demonstrated over a decade ago. However, only a few studies among PWID have since measured PrEP adherence using laboratory markers.

METHODS

In this trial, we randomized recently injecting PWID in Kyiv, Ukraine, to receive daily oral TDF/FTC with or without SMS reminders. Enrollment and PrEP initiation took place at an HIV clinic. Subsequent visits at months 1, 3, and 6 were conducted at a community harm reduction center and included a structured interview, adherence counseling, PrEP dispensing, and dried blood spot collection. PrEP adherence was assessed using standard self-reported measures and TDF/FTC biomarkers.

RESULTS

A total of 199 PWID (99 SMS, 100 No-SMS) were enrolled, of whom 24 % were women, with a median age of 37. At month 6, 79.4 % (158/199) of participants were retained, with 84 % (133/158) reporting opioid injection and 20 % (31/158) reporting stimulant injection in the past 30 days. 77 % (122/158) reported taking >95 % of PrEP doses in the past month, and 87 % reported taking the last dose within 2 days. Tenofovir diphosphate was detected in 17 % (28/158) of participants, and emtricitabine triphosphate was detected in 25 % (40/158). Only 3 % (5/158) had metabolite levels indicative of consistent PrEP uptake at 4+ doses per week. There was no association between the SMS intervention and TDF/FTC metabolite detection.

CONCLUSION

Adherence to daily oral PrEP among actively injecting PWID, without daily supervision or incentives, was extremely low, despite supportive counseling and SMS reminders. We also observed a high rate of discordance between self-report and classification by a validated biomarker of adherence. Given the scarcity of evidence and emerging data suggesting low oral PrEP adherence among PWID, additional implementation studies with TDF/FTC biomarkers are needed to study whether a sufficient level of adherence to daily PrEP is attainable among PWID, especially as long-acting injectable PrEP offers a promising alternative.