Factors associated with the development of systemic versus local infections in people who inject drugs (2026)

Objectives: To describe bacterial infections among people who inject drugs (PWID) in France, identify factors associated with systemic infection and define patient groups based on demographic and consumption profiles.
Methods: National, cross-sectional, multicenter study using spontaneous reports collected by the French Addictovigilance Network from January 2019 to December 2024. Local and systemic infections were compared to identify associated sociodemographic and injection-related factors. These variables were used to build patient profiles through hierarchical clustering approach.
Results: A total of 727 bacterial infections were analyzed (56% local and 44% systemic) in mainly men (79%), with a median age of 39 years. The most common infections were soft skin and tissue infections (65%), abscesses (51%), endocarditis (20%) and sepsis (15%). Cocaine (46.5%), heroin (16.5%) and buprenorphine (16.6%) were the main injected substances. Injecting stimulants only was associated with lower odds of systemic infection when compared to injecting a stimulants/opioids combination (OR 0.61 [95%CI: 0.40-0.93]) while older age (OR 1.02 [95%CI: 1.01-1.04]) and HIV-negative individuals not engaging in slam (OR 3.62 [95%CI: 1.46-8.98]) were associated with systemic infection compared to HIV-negative individuals engaging in slam. Five clusters were identified: I- Male, single substance injectors, opioids or stimulant, II- Female, single substance injectors, opioids or stimulant, III- Both opioids and stimulants injectors, IV- Young PWID, injectors of single substances outside opioids/stimulants presenting local infections, V- HIV-positive men, engaging in slam, having local infections.
Conclusion: Our findings illustrate how the type of psychoactive substances and the sociodemographic profile are related to the infection type among PWID. [Author's abstract]