Substance Use and HIV Risk in a Syndemic Context: Vulnerabilities Among African Refugee Sex Workers in Italy.

Substance use is a recognized driver of HIV vulnerability among sex workers, yet little is known about how behavioral patterns intersect with structural exclusion for African refugee male sex workers (RMSWs) in Europe. Guided by syndemic theory, we conducted an explanatory mixed-methods study in partnership with a community-based organization in Northern Italy. The qualitative strand included 20 in-depth interviews and two focus group discussions exploring experiences of substance use, stigma, and healthcare engagement. The quantitative strand comprised a structured survey of 150 RMSWs assessing changes in substance use before and after entering sex work and its associations with HIV-related outcomes. Substance use increased significantly following entry into sex work, with the largest rise observed for injectable drugs. Logistic regression and chi-square analyses revealed distinct patterns by substance type: injection use was associated with lower odds of STI disclosure, reduced enjoyment of sex work, and decreased willingness to use HIV self-testing, whereas non-injection use was linked to greater HIV service awareness, higher odds of disclosure, but also increased engagement in incentivized condomless sex. Chi-square tests further indicated that escalating tobacco, alcohol, and drug use were consistently associated with higher reports of healthcare stigma, immigration-related barriers, and reduced voluntary healthcare access. Qualitative findings contextualized these patterns, highlighting how stigma, financial precarity, and institutional exclusion shaped substance use trajectories and HIV risk. Integrated analysis underscores the need for interventions addressing structural discrimination and immigration-related barriers alongside behavioral HIV prevention for refugee sex workers.