Awareness of HIV Pre-Exposure Prophylaxis (PrEP) and Predictors of Interest in PrEP Among HIV-negative Persons Who Inject Drugs in Seattle, Washington

Background: HIV pre-exposure prophylaxis (PrEP) is safe and effective for use in people who inject drugs (PWID), but studies indicate that PrEP is underutilized in this population. We assessed awareness of PrEP and investigated predictors of interest in PrEP among PWID in Seattle, Washington. Methods: This study analyzed data from a 2019 survey of PWID at 3 Seattle-area syringe service programs (SSPs). PWID who injected drugs in the past three months and were HIV-negative by self-report were included. Descriptive statistics were used to compare PrEP-aware and unaware PWID, and multivariate Poisson regression with robust standard errors was used to estimate adjusted prevalence ratios (APR) for interest in PrEP. Results: Among 348 HIV-negative PWID, including ≤1% who were currently taking PrEP, 51% were knowledgeable of PrEP and 46% were interested in PrEP. Interest in PrEP was inversely associated with prior knowledge of PrEP (APR 0.58, 95% CI 0.45 – 0.74); however, interest in PrEP was high among a subset of PWID meeting pre-specified risk criteria for HIV (APR 1.53, 95% CI 1.09 – 2.15). Conclusion: Despite reasonably high knowledge of PrEP and interest in PrEP, current use of PrEP was strikingly low in this urban cohort of PWID. Increasing knowledge of PrEP among PWID may not be sufficient to improve access to and continued use of PrEP among PWID at highest risk for HIV.