Behavioral Risk Compensation after Initiation of Daily Oral Pre-Exposure Prophylaxis among Sexual and Gender Minorities in Nigeria.

Abstract Background: Pre-exposure prophylaxis (PrEP) effectively prevents HIV acquisition but may be associated with an elevated risk of other sexually transmitted infections (STIs) due to increased condomless anal intercourse (CAI) among sexual and gender minorities (SGM). We estimated the odds of self-reported CAI, concurrent sexual relationships with two or more male partners (concurrency), and sexually transmitted Infections (STIs)among SGM in Nigeria before and during the use of PrEP. Methods: This was anopen-label prospective study of SGM seen over four clinical visits between April 2018 and May 2019 as a nested study of the ongoing TRUST cohort study in Abuja, Nigeria. We identified participants who had been in the TRUST study on or before Feb 15, 2016, thereby providing at least 26 months of pre-PrEP initiation data for a “pre PrEP - PrEP” intervention analysis with participants serving as self-controls. Using conditional logistic regression, we estimated the odds ratio (ORs) and 95% confidence intervals (CIs) of PCR-diagnosed bacterial STIs (rectal Chlamydia trachomatis, rectal Neisseria gonorrhea, urethral Chlamydia trachomatis, and urethral Neisseria gonorrhea) and self-reported behavioral outcomes (CAI and concurrency). Results: Of the 400 SGM who initiated PrEP in this study, 206, with a median age of 24 years (interquartile range: 22-27) were eligible for these analyses. Compared with the pre-PrEP period, participants in the PrEP period had higher unadjusted odds of rectal gonorrhea (OR: 3.53, 95% CI: 1.10, 11.35) and decreased odds of self-reported CAI (OR: 0.57, 95% CI: 0.37, 0.87). There were no significant associations with other STIs or concurrency. In the adjusted analysis, after controlling for alcohol use in the past month, participants in the PrEP period had decreased odds of CAI (adjusted OR: 0.49, 95% CI: 0.28, 0.84). Conclusion: PrEP use was not associated with behavioral risk compensation among SGM in our study. However, there is a need for increased surveillance for STI screening and diagnosis among SGM using PrEP. These measures should complement ongoing behavioral risk-reduction counselling, emphasizing consistent condom use to prevent bacterial STIs while on PrEP.