BACKGROUND: Transgender women are disproportionately affected by HIV in Latin America. Although efficacious, PrEP adherence is a major issue among transwomen. PrEParadas is a demonstration study tailored for transwomen aiming to assess oral PrEP uptake, safety and adherence among transwomen at high risk for HIV in Rio de Janeiro, Brasil.
METHODS: HIV-negative transwomen, aged 18+ years, who reported 1+risk criteria (condomless anal sex in the last 6 months, sexually transmitted infection diagnosis in the last 12 months, transactional sex in the last 6 months, HIV-infected partner in the last 30 days) were enrolled and followed at 4 weeks and quarterly thereafter for 48 weeks. HIV viral load and dried blood spots (DBS) were collected at all follow-up visits. Anal Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) were assessed at w0 and w48. PrEP retention was defined by attendance of w48 visit; PrEP adherence was evaluated by measuring tenofovir diphosphate concentrations in dried blood spots (DBS) at all follow-up visits. We used GEE logistic regression to identify factors associated with high adherence (defined as TFV concentration in DBS correspondent to 4+ doses/week).
RESULTS: 130 transwomen initiated PrEP between Aug-2017 and Dec-2018, 109 (83.8%) were retained at w48. Anal CT and NG prevalence remained similar at w0 and w48 (CT: 7.7% and 8.3%, p=0.79; NG: 9.4% and 8.3%, p=0.88). Overall proportion of high PrEP adherence across all study visits was 57.0% (52.2% at w48). In the univariate analysis, black (OR=0.39 [95%CI:0.17-0.92]) and younger transwomen (OR=0.36 [95%CI:0.16-0.79] had a lower chance of high PrEP adherence across the study but did not remain significant in the adjusted model. Transwomen with high PrEP adherence at w4 had a higher chance of high adherence across the study (aOR=13.90, [95%CI: 6.30-30.87]). There were no HIV seroconversions during follow-up.
CONCLUSIONS: Even in a gender-affirming setting, achieving high PrEP adherence among transwomen remains a challenge, despite high retention, especially for those young and black. Strategies to support early PrEP adherence and to increase knowledge of PrEP as a self-empowering HIV prevention tool may contribute to longer-term PrEP adherence in that highly-vulnerable population.