Evaluating the effectiveness of ultraviolet-C lamps for reducing keyboard contamination in the intensive care unit: A longitudinal analysis

Background: Ultraviolet (UV) spectrum light for decontamination of patient care areas is an effective way to reduce transmission of infectious pathogens. Our purpose was to investigate the efficacy of an automated UV-C device to eliminate bioburden on hospital computer keyboards.

Methods: The study took place at an academic hospital in Chicago, Illinois. Baseline cultures were obtained from keyboards in intensive care units. Automated UV-C lamps were installed over keyboards and mice of those computers. The lamps were tested at varying cycle lengths to determine shortest effective cycles. Delay after use and prior to cycle initiation was varied to minimize cycle interruptions. Finally, 218 postinstallation samples were analyzed.

Results: Of 203 baseline samples, 193 (95.1%) were positive for bacteria, with a median of 120 colony forming units (CFU) per keyboard. There were numerous bacteria linked to health care-associated infections (HAIs), including Staphylococcus, Streptococcus, Enterococcus, Pseudomonas, Pasteurella, Klebsiella, Acinetobacter, and Enterobacter. Of the 193 keyboards, 25 (12.3%) had gram-negative species. Of 218 postinstallation samples, 205 (94%) were sterile. Of the 13 that showed bacterial growth, 6 produced a single CFU. Comparison of pre- and post-UV decontamination median CFU values (120 and 0, respectively) revealed a >99% reduction in bacteria.

Conclusions: The UV lamp effectively decontaminates keyboards with minimal interruption and low UV exposure. Further studies are required to determine reduction of HAI transmission with use of these devices.