Objective Our primary objective was to determine the effectiveness of two enhanced disinfection strategies compared to standard disinfection: "near-UV" light (Arm 1) and a persistent organosilane quaternary ammonium disinfectant (Arm 2) using a triple-blind study design. Our secondary objective was to characterize environmental contamination of outpatient clinics. Setting Wound and pulmonary outpatient clinics at Duke University Health System in Durham, North Carolina. Interventions In Arm 1,

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... om overhead lights were replaced with 405nm "near-UV" visible lightbulbs. In Arm 2, the organosilane quaternary ammonium disinfectant was applied to all room surfaces. The control arm received no intervention. All arms received routine disinfection. Room contamination was measured twice daily (before and after clinic) over 25 clinic days. Primary outcome The primary outcome was the change in total contamination, measured in colony forming units, (CFU) on environmental surfaces at the end of the clinic day compared to the beginning of the clinic day. Results from each intervention arm were compared against results from the control arm. Results The median delta total CFU for Arm 1 was 2,092 CFU [IQR: -1,815-8,566]; the median delta for Arm 2 was 2,016 CFU [IQR: -1,443-7,430]. Compared to the control arm (median delta = 1,987 [IQR: -1,611-15,857]), neither intervention led to a significant decrease in daily room contamination change (p for Arm 1=0.78 and p for Arm 2=0.71). Conclusion Neither "near-UV" lights or a persistent organosilane quaternary ammonium disinfectant reduced environmental contamination in two outpatient clinics compared to control rooms but did reduce the number of clinically important pathogens (CIPs) recovered.