HIV risk and oral pre-exposure prophylaxis (PrEP) among people who inject drugs (PWID) in Nairobi: a cross-sectional study

Persons who inject drugs (PWID) in Kenya face a high HIV burden (18% prevalence). Although oral pre-exposure prophylaxis (PrEP) is effective for HIV prevention among PWID, its awareness and use remain low. This study assessed HIV acquisition risk, oral PrEP knowledge, and uptake among PWID in Nairobi, Kenya. HIV-negative PWID were recruited from four drop-in centers in Nairobi (February–March 2022). HIV risk from sexual and injection practices was measured using the National Drug and Alcohol Research Centre’s HIV Risk-Taking Behavior Scale (HRBS). Oral PrEP awareness and uptake were assessed using the Low PrEP Awareness and Use among PWID tool. Analyses included descriptive statistics, unpaired t-tests (HRBS scores), chi-square tests (PrEP awareness and use), logistic regression (factors associated with PrEP awareness), and Fisher’s exact tests (PrEP uptake), conducted in SPSS version 24. Among 256 participants, 82.0% were male, 30.1% were on methadone, and 99.2% injected heroin. Mean HIV risk scores indicated moderate risk from injection practices (8.35/25) and sexual practices (11.59/30), totaling 19.94/55. HRBS scores were not associated with PrEP awareness (P = 0.493) or use (P = 0.727). Sexual HIV risk was higher among women than men (12.44/30 vs. 7.3/30; P < 0.001), and among those aged 18–24 versus 25–55 years (23.00/55 vs. 19.35/55; P = 0.016). PrEP awareness was 59.4%, but only 3.9% had ever used PrEP. Men were more likely than women to be aware of PrEP (84.8% vs. 53.8%; P < 0.001) and to have used it (13.0% vs. 1.9%; P < 0.001). PWID in Nairobi have a moderate HIV risk, with young and female PWID disproportionately affected. Despite moderate awareness, PrEP uptake is very low. Targeted PrEP education, gender-responsive outreach, and integration of PrEP into harm reduction services are needed to improve uptake. ClinicalTrials.gov Protocol Record STUDY0001370.