Use of Ultraviolet Irradiation in Addition to Commonly Used Hospital Disinfectants or Cleaners Further Reduces the Bioburden on High-Touch Surfaces

Background The reduction in microbial bioburden achieved by terminal disinfection in a hospital may vary considerably by type of disinfectant or cleaner and by environmental service (EVS) personnel. This study estimated whether supplemental ultraviolet (UV) irradiation after disinfection or cleaning reduced bioburden and whether the supplemental effect persisted after adjusting for disinfectant or cleaner type and EVS personnel. Methods Environmental samples for aerobic bacterial colonies (ABC) and methicillin-resistant Staphylococcus aureus (MRSA) were obtained from 5 high-touch surfaces in patient rooms at 3 time points: before manual cleaning, after manual cleaning using 1 of 3 disinfectants or 1 cleaner, and after UV irradiation. Results For ABC, the model-estimated mean (95% uncertainty interval) counts were 56% (48%–63%) lower for postmanual + UV compared with manual clean alone, and for MRSA they were 93% (62%–99%) lower for postmanual + UV vs manual clean alone. Conclusions Although UV supplementation provides incremental benefit in bioburden reduction across all cleaners or disinfectants tested, it provides the greatest benefit when supplementing cleaners or disinfectants with the lowest disinfection properties. UV irradiation provides additional bioburden reduction to manual cleaning or disinfection, even when accounting for variability introduced by different disinfectants and EVS personnel.