Effectiveness of an ultraviolet-C disinfection system for reduction of healthcare-associated pathogens

Background: Healthcare-associated infections caused by multidrug-resistant (MDR) pathogens are significantly associated with increased mortality and morbidity. Environmental cleaning can reduce transmission of these pathogens but is often inadequate. Adjunctive methods are warranted to enhance the effectiveness of disinfection particularly in hospital settings where healthcare-associated infections are of major concern. Methods: We conducted a study to examine the effectiveness of a mobile, automatic device, Hyper Light Disinfection Robot (model: Hyper Light P3), which utilized ultraviolet-C (UV-C) to kill MDR-Pseudomonas aeruginosa, MDR-Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VRE), Mycobacterium abscessus and Aspergillus fumigatus. The performance of this device in disinfecting hospital rooms previously admitted by patients harboring MRSA and VRE was also assessed. Results: Except for VRE and M. abscessus, more than 3 log(10) reduction of vegetative bacteria colonies was observed after UV-C irradiation of 5 min at a distance of 3 m from the device. At the distance of 1 m, substantial and comparable reduction of colonies was observed across all tested microorganisms regardless of exposure time. The killing effect was less pronounced for A. fumigatus particularly at the distance of 2-3 m. In uncleaned hospital rooms, there was significant reduction in the number of bacteria colonies sampled from different surfaces after UV-C irradiation for 15 min. Conclusions: UV-C disinfection system was effective in killing MDR pathogens. Further study is warranted to confirm its effectiveness as an adjunctive method in disinfecting hospital environment. Copyright (C) 2017, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC.