Contact time and disinfectant formulation significantly impact the efficacies of disinfectant towelettes against Candida auris on hard, non-porous surfaces

Background Candida auris is a globally emerging multidrug-resistant fungal pathogen. It causes healthcare-associated infections (HAIs) and can be transmitted through contaminated surfaces and equipment. Pre-wetted disinfectant towelettes are increasingly used for infection control. Our objective was to test the efficacies of EPA registered disinfectant towelette products, with or without fungicidal claims, against C. auris, on hard, non-porous surfaces below, at, and beyond label contact times. or longer contact times. We hypothesized that towelette disinfection efficacy against C. auris would be significantly influenced by chemistry and contact time. Methods We tested one hydrogen peroxide (HP), three quaternary ammonium (QAC), and one quaternary ammonium plus alcohol (QAC-alcohol)-based disinfectant towelette products, with or without EPA registered fungicidal claims, against C. auris Satoh et Makimura (ATCC MYA-5001). All products were tested at 30 s, one-, two-, three- and 10-min contact time to compare their overall efficacies on a defined surface area following modifications to standard EPA protocol MB-33-00. Results HP-based disinfectant towelettes were more efficacious against C. auris than the QAC-alcohol-based disinfectant towelettes irrespective of tested contact times. Thirty s contact time was significantly less effective in reducing C. auris from the Formica surface compared to one-, two-, three-, and 10-min contact times. However, there were no statistically significant differences in the level of disinfection among one-min and longer contact times regardless of product chemistry. None of the products achieved a standard six-log10 reduction at any tested contact times. Conclusion Overall, the HP-based disinfectant towelette was significantly more fungicidal than the QAC-alcohol-based disinfectant towelette. For all product types, 30 s contact time did not achieve the same level of disinfection as one-min or longer contact times. Overall, disinfectant towelette efficacy is dependent upon product formulation and contact time.