Disinfectant wipes transfer Clostridioides difficile spores from contaminated surfaces to uncontaminated surfaces during the disinfection process

Abstract

Background: Pre-wetted disinfectant wipes are increasingly being used in healthcare facilities to help address the risk of healthcare associated infections (HAIs). However, HAIs are still a major problem in the US with Clostridioides difficile being the most common cause, leading to approximately 12,800 deaths annually in the US. An underexplored risk when using disinfectant wipes is that they may cross-contaminate uncontaminated surfaces during the wiping process. The objective of this study was to determine the cross-contamination risk that pre-wetted disinfectant towelettes may pose when challenged with C. difficile spores. We hypothesized that although the tested disinfectant wipes had no sporicidal claims, they will reduce spore loads. We also hypothesized that hydrogen peroxide disinfectant towelettes would present a lower cross-contamination risk than quaternary ammonium products.

Methods: We evaluated the risk of cross-contamination when disinfectant wipes are challenged with C. difficile ATCC 43598 spores on Formica surfaces. A disinfectant wipe was used to wipe a Formica sheet inoculated with C. difficile. After the wiping process, we determined log₁₀ CFU on previously uncontaminated pre-determined distances from the inoculation point and on the used wipes.

Results: We found that the disinfectant wipes transferred C. difficile spores from inoculated surfaces to previously uncontaminated surfaces. We also found that wipes physically removed C. difficile spores and that hydrogen peroxide disinfectants were more sporicidal than the quaternary ammonium disinfectants.

Conclusion: Regardless of the product type, all disinfectant wipes had some sporicidal effect but transferred C. difficile spores from contaminated to otherwise previously uncontaminated surfaces. Disinfectant wipes retain C. difficile spores during and after the wiping process.

Keywords: Clostridioides difficile; Cross-contamination; Disinfectants.

Fig. 1

Schematic diagram of the Formica surface used for wipe testing. Two meters of Formica were delineated into 0.5 m² sections. 5.0 × 10⁸ log₁₀CFU C. difficile spores were spotted onto the inoculation zone (i-zone) as represented by red dots. The entire surface was wiped in an up and down motion across the entire surface as indicated by black outlined arrows from left to right. 10 cm × 10 cm (100 cm²) sampling zones (light gray squares) were sampled to recover potentially cross-contaminated spores

Fig. 2

Mean log₁₀ CFU/100 cm² remaining on sampled portions of the Formica sheet post disinfection with SH or hydrogen peroxide disinfectant wipes

Fig. 3

Mean log₁₀ CFU/100 cm² remaining on sampled portions of the Formica sheet post disinfection with SH or quaternary ammonium alcohol disinfectant wipes

Fig. 4

Mean log₁₀ CFU remaining on used wipes post disinfection with SH, hydrogen peroxide or quaternary ammonium alcohol disinfectant wipes. Bars with the same Turkey letter are statistically similar