Analysis of bacterial contamination and the effectiveness of UV light-based reprocessing of everyday medical devices

Abstract

Background The reprocessing of daily used medical devices is often inadequate, making them a potential source of infection. In addition, there are usually no consistent and technically standardized procedures available for this purpose. Hence, the aim of this study is to analyze the bacterial contamination and the effectiveness of Ultraviolet light-based (UV light-based) reprocessing of daily used medical devices. Material and methods Six different everyday medical devices (20 each; stethoscopes, tourniquets, bandage scissors, reflex hammers, tuning forks, and nystagmus glasses) were tested for bacterial contamination. All medical devices were then exposed to UV-C light for 25 seconds. Medical devices with a smooth surface were pre-cleaned with a water-based wipe. Contact samples were taken before and after reprocessing. Results Immediately after clinical use, 104 of 120 contact samples showed an average bacterial contamination of 44.8±64.3 colony forming units (CFU) (0–300 CFU), also including potentially pathogenic bacteria. Two further culture media were completely overgrown with potentially pathogenic bacteria. The stethoscopes were found to have the highest average contamination of 90±91.6 CFU. After reprocessing, 118 of 120 samples were sterile, resulting in an average residual contamination of 0.02±0.1 CFU in two samples, whereby only bacteria of the ordinary skin flora were found. Conclusion The present study shows the potentially clinically relevant bacterial contamination of everyday used medical devices. The reprocessing method tested here using UV light appears to be a suitable method for disinfection, especially for objects that up to now have been difficult to disinfect or cannot be disinfected in a standardized manner.

Ultraviolet-C (UV-C) Effectiveness for Bacterial Decontamination in The Hospital Setting: A Systematic Review

“…The results included one article in the "critical," 2 in the "high," three in the "moderate," and seven in the "low" category. The "critical" classification for the risk of bias assessment in the study of Rudhart et al (2022) was due to the sample that was too varied with an unequal number per type of sample, even though all of them were classified as semi-critical medical devices. In addition, there was no single standard for each contamination and control group to compare interventions.…”

“…The disinfection process simply uses low-level disinfectants (26). Rudhart et al, (2022) and Sebastian Marcos et al, (2020) results showed that the reduction of bacteria in non-critical devices ranges from 67.9% to sterile (100% bacteria-free) after UV-C exposure. Pre-cleaning using water wipes can be applied to apparently dirty or non-critical objects with surfaces that tend to be uneven, thereby allowing a lot of dirt to be tucked in.…”

Inactivation of SARS CoV-2 on porous and nonporous surfaces by compact portable plasma reactor

“…They were then sprayed with 70% molecular grade ethanol to decontaminate their surfaces and left to air-dry, then placed into open sterile plastic petri dishes. The coupons in the petri dishes were then irradiated on each side for 5 min using the sterilizing UV light within the BSC for a more thorough surface decontamination step ( Rudhart et al, 2022 ; Rutala et al, 2023 ). Post UV-irradiation, lids were placed on the petri dishes, which were then labelled and stored for experimental runs.…”

Disinfection of Transparent Screens by Side-Coupled UVA LED Radiation

“…To prevent the transmission of pathogens via displays, there would have to be fast automatic disinfection between two users. In theory, it is possible to reduce bacteria on surfaces within seconds by using strong UVC radiation sources (UVC: ultraviolet radiation between 100 and 280 nm) such as mercury vapor lamps, as has already been proven by Rudhart et al (2022), Petersson et al (2015), Moore et al (2012) [5][6][7] and others. Unfortunately, UVC radiation could also harm humans in case of an accidental irradiation [8][9][10][11][12].…”