Pre-exposure prophylaxis implementation gaps among people vulnerable to HIV acquisition: a cross-sectional analysis in two communities in western Kenya, 2021-2023.

Introduction: Despite the increasing availability of prevention tools like pre-exposure prophylaxis (PrEP), HIV incidence remains disproportionately high in sub-Saharan Africa. We examined PrEP awareness, uptake and persistence among participants enrolling into an HIV incidence cohort in Kenya.

Methods: We used cross-sectional enrolment data from the Multinational Observational Cohort of HIV and other Infections (MOCHI) in Homa Bay and Kericho, Kenya. The cohort recruited individuals aged 14-55 years with a recent history of sexually transmitted infection, transactional sex, condomless sex and/or injection drug use. Participants completed questionnaires on PrEP, demographics and sexual behaviours. We used multivariable robust Poisson regression to estimate adjusted prevalence ratios (aPRs) and 95% confidence intervals (CIs) for associations with never hearing of PrEP, never taking PrEP and ever stopping PrEP.

Results: Between 12/2021 and 5/2023, 399 participants attempted the PrEP questionnaire, of whom 316 (79.2%) were female and median age was 22 years (interquartile range 19-24); 316 of 390 participants (81.0%) engaged in sex work or transactional sex. Of 396 participants who responded to the question, 120 (30.3%) had never heard of PrEP. Of 275 participants who had heard of PrEP, 206 (74.9%) had never taken it. Of 69 participants who had ever taken PrEP, 50 (72.5%) stopped it at some time prior to enrolment. Participants aged 15-19 years more often reported never taking PrEP compared with those 25-36 years (aPR 1.31, 95% CI: 1.06-1.61). Participants who knew someone who took PrEP less often reported never hearing about PrEP (aPR 0.10, 95% CI: 0.04-0.23) and never taking PrEP (aPR: 0.69, 95% CI: 0.60-0.80). Stopping PrEP was more common among participants with a weekly household income ≤1000 versus >1000 Kenyan shillings (aPR 1.40, 95% CI: 1.02-1.93) and those using alcohol/drugs before sex (aPR 1.53, 95% CI: 1.03-2.26). Stopping PrEP was less common among those engaging in sex work or transactional sex (aPR 0.6, 95% CI: 0.40-0.92).

Conclusions: We identified substantial gaps in PrEP awareness, uptake and persistence, which were associated with potential system- and individual-level risk factors. Our analyses also highlight the importance of increasing PrEP engagement among individuals who do not know others taking PrEP.