Comparison of ultraviolet C light and isopropyl alcohol for the disinfection of cellular phones in a paediatric intensive care unit setting

Abstract

Background. A considerable proportion of cellular phones (cell phones) used by healthcare workers (HCWs) have been shown to be contaminated with pathogenic micro-organisms, making these devices reservoirs to infect susceptible patients. Although many units have well-defined infection control protocols, methods for the decontamination of cell phones are scarce. Objectives. To compare the efficacy of ultraviolet C (UVC) light with that of 70% isopropyl alcohol in disinfecting cell phones used by HCWs in a paediatric intensive care unit (ICU). Methods. A randomised controlled study in a paediatric ICU setting was conducted. Cell phones of HCWs or other personnel entering the ICU were swabbed prior to and after decontamination with either the 70% isopropyl alcohol or UVC light method. The reduction ratio of colony-forming units (CFUs) before and after intervention was analysed using the Mann-Whitney U-test. In addition, the effectiveness of the disinfection methods was compared using the Wilcoxon signed-rank paired test. Results. A total of 74 cell phones were acquired from HCWs working in the paediatric ICU. After excluding 5, 69 samples were therefore available for statistical analysis, with 34 samples subjected to disinfection using 70% isopropyl alcohol-based swabs and 35 samples treated with UVC light disinfection. Disinfection with 70% isopropyl alcohol (z=5.16; p<0.000001) and with UVC light (z=3.28; p<0.005) were individually statistically significantly effective in reducing CFUs. The CFU reduction ratio indicated that disinfection using a 70% isopropyl alcohol solution was 67% more effective than UVC light disinfection (Mann-Whitney U-test score 968; p<0.001). Conclusion. Although both 70% isopropyl alcohol and UVC light disinfection effectively reduced CFUs following decontamination, 70% isopropyl alcohol was determined to be much more effective.