Comparison of hospital room surface disinfection using a novel ultraviolet germicidal irradiation (UVGI) generator

ABSTRACT

The estimated 721,800 hospital acquired infections per year in the United States have necessitated development of novel environmental decontamination technologies such as ultraviolet germicidal irradiation (UVGI). This study evaluated the efficacy of a novel, portable UVGI generator (the TORCH, ChlorDiSys Solutions, Inc., Lebanon, NJ) to disinfect surface coupons composed of plastic from a bedrail, stainless steel, chrome-plated light switch cover, and a porcelain tile that were inoculated with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus faecalis (VRE). Each surface type was placed at 6 different sites within a hospital room and treated by 10-min ultraviolet-C (UVC) exposures using the TORCH with doses ranging from 0–688 mJ/cm² between sites. Organism reductions were compared with untreated surface coupons as controls. Overall, UVGI significantly reduced MRSA by an average of 4.6 log₁₀ (GSD: 1.7 log₁₀, 77% inactivation, p < 0.0001) and VRE by an average of 3.9 log₁₀ (GSD: 1.7 log₁₀, 65% inactivation, p < 0.0001). MRSA on bedrail was reduced significantly (p < 0.0001) less than on other surfaces, while VRE was reduced significantly less on chrome (p = 0.0004) and stainless steel (p = 0.0012) than porcelain tile. Organisms out of direct line of sight of the UVC generator were reduced significantly less (p < 0.0001) than those directly in line of sight. UVGI was found an effective method to inactivate nosocomial pathogens on surfaces evaluated within the hospital environment in direct line of sight of UVGI treatment with variation between organism and surface types.

KEYWORDS:

• Decontamination
• hospital room
• surfaces
• ultraviolet disinfection
• UVGI

Acknowledgments

The authors thank Nathan Harms for his contributions in the laboratory processing of organisms and Michelle Schwedhelm, Kathleen Boulter, and Angela Vasa from Nebraska Medicine for coordinating access to the Nebraska Biocontainment Unit.

Funding

The work was financially supported by the University of Nebraska Medical Center and Nebraska Biocontainment Unit. The TORCH is on loan to the research group from ChlorDiSys Solutions, Inc. However, ChlorDiSys is not part of the research team, party to experimental design, or aware of the results of the article ahead of print. ChlorDiSys has put no conditions on the use of the TORCH beyond that the instrument be returned when the study is completed. No authors have any financial disclosures.