HIV Prevention Among People Who Inject Drugs (PWID): A Narrative Review.

People who inject drugs (PWID) face a significantly higher risk of HIV infection than the general population. Effective prevention for this group depends on combining several strategies: needle and syringe programs (NSPs), opioid agonist therapy (OAT), antiretroviral therapy (ART), pre-exposure prophylaxis (PrEP), overdose prevention, and changes to structural and policy environments. This narrative review draws on evidence published between 2000 and 2024, including systematic reviews, clinical trials, surveillance reports, and global health guidelines. Programs that offer high coverage of NSPs and OAT have consistently been shown to reduce HIV incidence. ART helps lower viral load and prevents transmission, while both daily and long-acting PrEP offer additional protection for those at risk. However, access remains limited, particularly in low- and middle-income countries, due to criminalization, stigma, and a lack of investment in harm reduction services. Outcomes vary widely by region. In places like Portugal and Canada, where policies support decriminalization and integrate harm reduction into routine care, HIV incidence among PWID has dropped significantly. In contrast, countries that maintain punitive drug laws, such as Russia, continue to struggle with sustained epidemics. Reducing HIV transmission in this population will require expanding access to proven interventions, integrating services more effectively, and reforming policies that act as barriers to care. Priorities moving forward include scaling up NSP and OAT, addressing gender-based inequities, reducing stigma, and aligning national policies with international harm reduction standards.