Evaluation of an automated far ultraviolet-C light technology for decontamination of surfaces and aerosolized viruses in bathrooms
Claire E. Kaple, Samir Memic, Jennifer L. Cadnum, Curtis J. Donskey
Abstract
Abstract Background Aerosols generated during toilet flushing are a potential source for transmission of viral and bacterial pathogens in bathrooms. However, manual decontamination of bathrooms after each use is not feasible. Methods We tested the efficacy of a wall-mounted far ultraviolet-C (UV-C) light technology that only delivers far UV-C when people are not present for decontamination of surfaces and aerosolized viral particles in an unoccupied hospital bathroom. A quantitative disk carrier test method was used to test efficacy against organisms on steel disk carriers placed in 9 sites in the bathroom with an exposure time of 45 min and 2 h; Clostridioides difficile spores were also exposed for 24 h. Efficacy against aerosolized bacteriophage MS2 was tested with a 45-minute exposure. Results The far UV-C technology reduced methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), Candida auris , and bacteriophage MS2 on steel disk carriers by ≥ 1.2 log 10 (range, 1.2 to 4.2 log 10 ) at all test sites after 2 h of exposure. The technology reduced C. difficile spores by < 1 log 10 after 2 h exposure, but 4 of 9 test locations had ≥ 2 log 10 reductions after 24 h exposure. Aerosolized bacteriophage MS2 was reduced by 4 log 10 plaque-forming units in 45 min. Conclusions The far UV-C light technology could potentially be useful for automated decontamination of air and surfaces in bathrooms in healthcare and community settings.