Candida auris — An Emerging and Difficult Threat

Candida auris (C. auris) is receiving national media attention, and was a hot topic at the recent SHEA 2019 and APIC 2019 conferences, where infection prevention researchers discussed how to control and prevent potentially deadly and costly infections caused by this healthcare-acquired fungus.

C. auris is top of mind for healthcare facilities because of continued outbreaks and difficulty in controlling and preventing C. auris infections. This threat is particularly concerning because of the emergence of multidrug and panresistant strains, difficulty in properly diagnosing infections, long colonization time, and because it can be difficult to kill with surface disinfectants.

C. auris was first recognized as an emerging threat in 2009, and infections have been reported in more than 20 countries since that time. In the U.S., infections have appeared primarily in New York, New Jersey, and Illinois. But, previous pathogen outbreaks have spread quickly across the U.S., and it is likely that C. auris will follow suit.

From a surface disinfection standpoint, C. auris has been shown to persist on environmental surfaces for at least seven days (some sources have suggested up to 30 days), and shared and mobile equipment have been implicated in the spread of this pathogen in healthcare facilities.

There are currently very few disinfectants that carry claims against C. auris on label. Because of this, the Centers for Disease Control and Prevention (CDC) currently recommends using a disinfectant with a claim against Clostridioides difficile (C. diff) spores. Most of these disinfectants can be found on the Environmental Protection Agency’s (EPA) List K, which is a list of registered hospital-grade disinfectants effective against C. diff spores.

List K currently includes mostly bleach-based products; however, the CDC notes that some alternate disinfectants with other active ingredients like hydrogen peroxide have been shown to kill C. auris, as demonstrated in a recent article published by Dr. Curtis Donskey at Louis Stokes Cleveland VAMC.

The CDC also cautions that quaternary ammonium-based disinfectants may not be effective against C. auris, which Dr. Donskey’s study confirms. Additionally, they note that limited data is available on the effectiveness of UV. However, some UV devices have been shown to be effective against C. diff, and may be an effective adjunct for C. auris disinfection.

For more on C. auris, see the CDC website. The EPA’s List K can be found on the EPA website. To read the full studies discussed in this article, see Cadnum, et al., 2018, Piedrahita, et al., 2017, and Rutala, et al., 2017.