Potential self‐disinfection capacity of touch screen displays

Abstract

Touch screen displays are potential pathogen reservoirs and involved in the spread of hospital acquired infections. They emit visible light that is known for a weak but proven antimicrobial photoinactivation effect, so the question is whether displays have the potential to disinfect themselves. To test the antimicrobial capacity of touch screen displays, Staphylococcus carnosus are distributed on Samsung tablets and illuminated for up to 36 hours. The average number of colony forming units decreases with time with white light being the most efficient followed by blue, green and red light. Increasing the illumination intensity by a mirror leads to a faster bacterial decrease up to a 90% reduction in 15 hours. A 99.99% reduction of staphylococci should be possible by turning on the display over the weekend.

Disinfection Properties of Conventional White LED Illumination and Their Potential Increase by Violet LEDs for Applications in Medical and Domestic Environments

“…Rutala et al [19] investigated the antimicrobial effect of white light with a noticeable staphylococci reduction even for low irradiation doses. These results fit to an own study, in which we investigated the disinfecting properties of a touch screen, and observed that a highly luminous blue screen was capable of pronounced bacterial reduction, while a white luminous screen, for which the light was a combination of red, green, and blue emissions, was even slightly more effective [20].…”

Disinfection of Transparent Screens by Side-Coupled UVA LED Radiation

“…For the purposeful contamination of the glass plates with staphylococci, the glass panes were first manually cleaned and disinfected with a 70% ethanol solution for about 10 min and thereafter exposed to the UVC radiation of a low-pressure mercury vapor lamp for at least half an hour. In order to obtain adequate bacterial concentrations and distribute them evenly over the glass plate surface, the following procedure was performed, which was previously described in [21]: An industrial paper towel (Glaeser, Ulm, Germany) was placed on the plate, and with a Pasteur pipette a volume of approximately 7 mL of bacterial test solution was manually and evenly distributed over the towel and the glass pane. After about 1.5 h, the towel was dry and was removed.…”