1222. Are Reduced Concentrations of Chlorine-Based Disinfectants Effective Against Candida auris?

BACKGROUND: Currently, sporicidal disinfectants such as bleach are recommended for daily and terminal disinfection of the rooms of patients with Candida auris colonization and/or infection. However, bleach and other chlorine-based disinfectants can have adverse effects on surfaces and personnel. Disinfectant solutions with reduced chlorine concentrations are commonly used for other pathogens, but it is not known if diluted or alternative products maintain efficacy against C. auris both in vitro and in vivo. METHODS: We tested the efficacy of different concentrations of a sodium dichloroisocyanurate (NaDCC) product and sodium hypochlorite using the method recommended by the Environmental Protection Agency (EPA) for evaluation of the efficacy of liquid disinfectants against C. auris (EPA MLB SOP MB-35-00) and in a simulated patient room. Carriers were exposed to each disinfectant for 1 and 2 minutes. Log reductions were calculated by subtracting viable organisms recovered after disinfectant exposure vs. deionized water controls. RESULTS: As shown in the figure, the NaDCC product at 4306 ppm tested with a 2 minute contact time reduced C. auris by ≥5 log(10) colony-forming units (CFU) but had reduced efficacy with shorter exposure time or lower concentrations. Sodium hypochlorite was effective with 1 or 2 minute exposure times at a concentration of 6,500 ppm, and was effective at 4,000 ppm with an exposure time of 2 minutes. In the simulated patient room, NaDCC reduced C. auris contamination by ≥6 log(10) CFUs on all surfaces. CONCLUSION: A chlorine-based NaDCC product was effective at reducing C. auris. Both NaDCC and sodium hypochlorite products exhibited reduced efficacy at lower concentrations, particularly at concentrations below 4000 ppm. The NaDCC products were also effective in reducing contamination in the simulated patient room. UV-C treatment was an effective adjunct to manual cleaning. [Image: see text] DISCLOSURES: All authors: No reported disclosures.