Implementation of the Infection Risk Scan in a hospital network by the Hospital Outbreak Support Team The Infection Risk Scan (IRIS) assesses the quality of infection prevention and control (IPC) and antimicrobial stewardship (AMS) in a hospital ward by the standardized measurement of a broad range of quality indicators. IRIS was implemented in the geriatric wards of the 4 hospitals of the Plexus healthcare network ‘Oost-Vlaams-Brabant’ (Belgium). The goal was to compare the IPC and AMS policies of the hospitals in order to define common improvement strategies within the Hospital Outbreak Support Team (HOST), a federal project concerning IPC and AMS. In the first part of IRIS, the risk profile of the patient population is determined by a point prevalence measurement of 4 variables. In the second part, the improvement plot is created based on the measurement of 7 quality indicators. Improvement actions can be deduced from quality indicators with higher improvement potentials. The risk profiles of the 4 hospitals were highly comparable and the improvement plots showed an intermediate to high improvement potential for the use of AMT and hand hygiene compliance. There were important differences in the appropriate use of transurethral and intravascular catheters, with 2 hospitals having a low and 2 hospitals having a high improvement potential. IRIS was a useful tool in the early phase of the HOST project to benchmark the IPC and AMT policies between the Plexus hospitals and to decide what future projects could be collaborated on. As a result of IRIS, it was decided to define common care bundles for the prevention of catheter-associated urinary tract and blood stream infections and to determine hospital-specific actions with regard to the optimisation of AMS.