Costanza Vicentini, Roberta Bussolino, Elisabetta Kuczewski, Christelle Elias, Anaïs Machut, Sara Bettoni, Matilde Perego, Luca Bresciano, Lorenzo Ramondetti, A. Friggeri, Alain Lepape, Zotti Cm, Stefano Finazzi, Fulvio Agostini, Laurent Argaud, Nicoletta Barzaghi, Yasmina Berrouane, Julien Bohé, Cesare Bolla, Valeria Bonato, Elisabetta Brizio, Pietro Caironi, Vanessa Chartier, Jullien Crozon-Clauzel, Andrea Dalla Selva, Sophie Debord-Peguet, Géraldine Dessertaine, Salvatore Di Blasi, Francesco Di Nardo, Gilberto Fiore, Marion Gleize, Béatrice Grisi, Scipione Gatti, Veronica Gavinelli, H. Hyvernat, Caroline Landelle, Anne-Claire Lukaszewicz, Agostino Maiello, Philippe Mardrus, Alessandro Mastroianni, Barbara Mitola, Giorgia Giuseppina Montrucchio, E. Munier-Marion, Carlo Olivieri, Ossola, Rémi Plattier, Christian Pommier, Thomas Rimmelé, Jean-Christophe Richard, Maurizio Salvatico, Paola Selvaggi, Daniela Silengo, Paola Silvaplana, Carlo Silvestre, Paola Rosa Soldà, Pasquale Toscano, Caterina Vaccari, Valentina Venturino, Emmanuel Vivier, F. Wallet
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.