Carbapenem-resistant Acinetobacter baumannii infections in intensive care units: incidence, infection prevention and control, and antimicrobial stewardship practices in the cross-border region between Italy and France, 2019–2022

BACKGROUND: Carbapenem-resistant Acinetobacter baumannii (CRAB) is a priority-1 critical pathogen with limited treatment options and high mortality among intensive care unit (ICU) patients. Italy reports hyperendemic levels, whereas France maintains low prevalence. Understanding cross-border differences is essential to inform infection prevention and control (IPC) and antibiotic stewardship strategies. AIM: We investigated incidence trends of CRAB infections in ICUs across the French-Italian border and assessed structural, organizational, IPC, and stewardship practices to identify factors associated with infection risk. METHODS: We conducted a multi-centre observational study involving ICUs of four cross-border regions (Piemonte, Valle d'Aosta, Auvergne-Rhône-Alpes, and Provence-Alpes-Côte d'Azur). Data on ICU-acquired bloodstream infections (BSI), central-line-associated BSI, pneumonia, and ventilator-associated pneumonia with CRAB isolates were extracted from the GiViTI and Réa-Rézo surveillance systems (2019-2022). A structured survey explored ICU characteristics, IPC, and stewardship practices. Logistic regression analysis was performed to identify factors associated with CRAB infection episodes. RESULTS: Overall, 25 ICUs participated in data collection. Among 24,822 ICU admissions, the proportion of A. baumannii isolates that were carbapenem resistant was 18.75% (95% confidence interval [CI]: 7.97-34.98) in France and 83.56% (95% CI: 80.1-86.63) in Italy. Different approaches to IPC and antibiotic stewardship were highlighted. Structural ICU design, staffing flexibility, and resilient IPC and stewardship practices were associated with lower infection risk. CONCLUSION: The CRAB incidence was substantially higher in Italy than in France. Cross-border harmonization of surveillance and co-ordinated preventive strategies are critical to contain cross-border spread.