Silver-ion disinfectant keeps operating room surfaces germ-free for hours longer than quaternary ammonium

A multicenter randomized controlled trial has found that a hydrogen peroxide-based disinfectant containing silver ions kept high-touch operating room surfaces free of detectable microbes for at least four hours after cleaning, while surfaces treated with conventional quaternary ammonium compounds were fully recontaminated within the same period. The study, published in Antimicrobial Resistance & Infection Control, was registered with the UMIN Clinical Trials Registry and carried out across four teaching hospitals.

Contaminated environmental surfaces in operating rooms are considered a potential source of microbial transmission and may raise the risk of surgical site infections. Quaternary ammonium compounds, or QACs, have long been a standard choice for disinfecting these surfaces, but their limited residual antimicrobial activity allows surfaces to become rapidly recontaminated after the initial wipe. The research team compared this traditional approach against a solution combining hydrogen peroxide with silver ions, referred to as HP-Ag, which is designed to leave a persistent antimicrobial residue on treated surfaces.

In the trial, 50 operating rooms were randomly allocated to receive either HP-Ag or QAC disinfection. Six predefined high-touch surfaces in each room were sampled at four time points: before disinfection, immediately after, two hours after, and four hours after the cleaning procedure. At the same time, 400 patients undergoing elective general surgery in these operating rooms were prospectively monitored for 30 days to track the development of surgical site infections.

Both disinfectants performed identically in their immediate effect, achieving complete microbial eradication with a median count of 0.0 CFU/mL right after application. The difference emerged in the hours that followed. Four hours after disinfection, microbial counts on HP-Ag-treated surfaces remained at 0.0 CFU/mL, whereas surfaces treated with QAC showed a median of 20.0 CFU/mL, a difference that was statistically significant with P < 0.001.

Recontamination rates told a similar story. At the four-hour mark, 29.3 percent of surfaces disinfected with HP-Ag had been recontaminated, compared with 100 percent of QAC-treated surfaces, again with P < 0.001. The researchers attribute this sustained effect to the residual activity of silver ions, which continue to suppress microbial growth on the surface after the initial disinfection step has been completed.

The trial also followed patients for clinical outcomes, though this was a secondary aim. The 30-day surgical site infection incidence showed a lower trend in the HP-Ag group, at 1.0 percent versus 4.5 percent in the QAC group. However, this difference did not reach statistical significance, with P = 0.062 by Fisher’s exact test, and the study was primarily powered for environmental outcomes rather than clinical endpoints.

The authors are careful to frame the infection findings as exploratory. In their conclusions, they state that while the enhanced environmental hygiene showed a trend toward lower postoperative surgical site infection rates, the difference was not statistically significant and remains a secondary, exploratory finding. They note that larger, appropriately powered clinical trials are required to definitively establish a causal link between persistent environmental disinfection and improved patient outcomes.

The study’s design carries some limitations worth noting. The trial was retrospectively registered on 28 August 2026, and the clinical outcome analysis involved 400 elective general surgery patients across the participating hospitals, a sample size that may have been insufficient to detect a modest difference in infection rates. The findings also apply specifically to the six high-touch surfaces sampled and to elective general surgical procedures in teaching hospital settings, so generalization to other surgical specialties or facility types would require further study.

Nevertheless, the environmental results are striking. The near-total prevention of recontamination over four hours represents a meaningful contrast with the rapid rebound in microbial counts observed with quaternary ammonium disinfection, which allowed every sampled surface to be recontaminated within the same window. If confirmed in larger trials with clinical endpoints as the primary outcome, residual disinfectants of this type could become a useful addition to operating room hygiene protocols aimed at reducing the microbial burden on surfaces between cleaning cycles and surgical procedures.

Subject of Research: Residual antimicrobial efficacy of silver-ion/hydrogen peroxide versus quaternary ammonium disinfection on operating room surfaces

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

Article References: Pourdel, B., Rajabi, E., Memarbashi, E., & Hosseini, S. A. (2026). Sustained antimicrobial efficacy of silver-ion/hydrogen peroxide versus quaternary ammonium on high-touch operating room surfaces: a multicenter randomized controlled trial. Antimicrobial Resistance & Infection Control. https://doi.org/10.1186/s13756-026-01849-x

Image Credits: AI Generated

DOI: 10.1186/s13756-026-01849-x

Keywords: operating room, surface disinfection, silver ions, hydrogen peroxide, quaternary ammonium compounds, surgical site infections, randomized controlled trial, antimicrobial resistance, hospital hygiene, recontamination, Sustained, antimicrobial