Is the combination of UV-C light and bleach less effective than bleach alone for intensive care unit surface disinfection?

• Published in: Infection prevention in practice Vol. 5; no. 4; p. 100307
• Main Authors: Shek Daud, Nur Shazlin, Dunn, Mark, Moncayo-Nieto, Olga Lucia, Hay, Alasdair
• Format: Journal Article
• Language: English
• Published: England Elsevier 01-12-2023
• Subjects: Bleach; Cleaning; Disinfection; Ultraviolet-C light; Disinfection; Bleach; Cleaning; Ultraviolet-C light
• ISSN: 2590-0889; 2590-0889
• DOI: 10.1016/j.infpip.2023.100307

Chlorine-based disinfectants, such as bleach, are commonly used for cleaning in healthcare settings to prevent the transmission of nosocomial pathogens. To enhance the efficacy of disinfection, ultraviolet-C (UV-C) light systems have been proposed to supplement standard cleaning procedures. As bleach decomposes in UV light, we hypothesised that the use of UV-C light as an adjunct to manual cleaning with bleach, may decrease the efficacy of disinfection instead.
In the laboratory, stainless steel sheets and plastic keyboards were inoculated with
(∼10
CFU/ml) and subjected to treatment with either UV-C light only, bleach only or a combination of UV-C light and bleach. The residual bioburden (CFU/ml) was quantified through conventional microbiological techniques. Results were compared to non-exposed control surfaces and against each treatment strategy.
On tested surfaces, there were statistically significant reductions in
when surfaces were treated with UV-C light only (>2.5 log
reduction), bleach only (>5.6 log
reduction) and a combination of UV-C light and bleach (>6.3 log
reduction) compared to positive control (
< 0.001, all treatment strategies). No significant differences were observed when surfaces were treated with the addition of UV-C light to bleach compared to treatment with bleach alone.
There was no difference in the efficacy of disinfection against
with the combined treatment strategy of UV-C light and bleach compared to bleach alone under laboratory conditions. Further studies are warranted to elucidate the effectiveness of this technology on other healthcare-associated pathogens.