Sustained antimicrobial efficacy of silver-ion/hydrogen peroxide versus quaternary ammonium on high-touch operating room surfaces: a multicenter randomized controlled trial

Contamination of environmental surfaces in the operating room (OR) is a potential source of microbial transmission, increasing the risk of surgical site infections (SSIs). Although quaternary ammonium compounds (QACs) are traditionally used, their limited residual antimicrobial properties allow rapid surface recontamination. This study compared the residual antimicrobial effects of silver ions in a hydrogen peroxide-based (HP-Ag) solution against QACs on high-touch OR surfaces. In this multicenter randomized controlled trial, 50 operating rooms across 4 teaching hospitals were randomly allocated to receive either HP-Ag or QAC disinfection. Six predefined high-touch surfaces were sampled at 4 time points: pre-disinfection, immediately after, 2 h after, and 4 h after disinfection. Simultaneously, 400 patients undergoing elective general surgeries in these ORs were prospectively monitored for 30-day SSI development. Both disinfectants demonstrated complete immediate microbial eradication (median = 0.0 CFU/mL). However, residual antimicrobial efficacy was significantly higher in the HP-Ag group. Four hours post-disinfection, microbial counts remained at 0.0 CFU/mL in the HP-Ag group compared to 20.0 CFU/mL in the QAC group ( P < 0.001). Surface recontamination at 4 h occurred in 29.3% of HP-Ag treated surfaces versus 100% of QAC surfaces ( P < 0.001). The 30-day SSI incidence showed a lower trend in the HP-Ag group (1.0% vs. 4.5%, P = 0.062, Fisher’s exact test), though the study was primarily powered for environmental outcomes. HP-Ag disinfection provided superior persistent microbial reduction on OR surfaces compared to QACs due to the residual activity of silver ions. While this enhanced environmental hygiene showed a trend toward lower postoperative SSI rates, this difference did not reach statistical significance and remains a secondary, exploratory finding. Larger, appropriately powered clinical trials are required to definitively establish a causal link between persistent environmental disinfection and improved patient outcomes. UMIN Clinical Trials Registry (UMIN-CTR), UMIN000062729. Registered on 28 August 2026. Retrospectively registered.