Light-Activated Antimicrobial Therapy to Prevent Surgical Site Infections

This study employs a group-randomized crossover design, comparing outcomes from the treatment group with that of a standard-of-care control group from the same hospitals. Each hospital ('site') engaged in the study will be randomly assigned to treatment plus standard-of-care or standard-of-care control on a 1:1 basis and will enroll patients into those respective groups during the first period of the study. After an approximate 6-week inactive interval period, each site will crossover to enroll the alternate group, up to a number of patients that matches the site's first period (or up to 10% more). Eligible patients who successfully complete all screening assessments and meet inclusion and exclusion criteria will be enrolled. Patients in the treatment group will undergo aPDT treatment after admission to the preoperative area. All patients will be followed up for a 30-day post-surgery period. A patient-reported outcome (PRO) assessment to gauge the tolerability of the intervention after administration will also be performed in the treatment group. Standard-of-care infection control practices will be applied according to infection prevention policies and procedures in place at each hospital. These practices are to remain unchanged for both groups throughout the study. Microbiological samples will also be collected from any SSI and evaluated to establish the causative organism and its antibiotic susceptibility. The incidence of SSIs during the 30-day postoperative period will be tracked to ensure comprehensive follow-up evaluations. In-person unscheduled visits will be conducted for medical assessment of suspected SSIs and collection of wound cultures. Nasal Microbiota Substudy Approximately 500 study patients will have pre-treatment and post-treatment nasal swabs (in the treatment group) or single pre-surgical nasal swabs (in the control group) collected and stored. These samples will be processed for quantitative microbiological evaluation of S. aureus.