Breaking the Unbroken Chain of Transmission: Candida auris in 2020-2021

Author: Marc-Oliver Wright, MT(ASCP), MS, CIC, FAPIC

As the SARS-CoV-2 pandemic has rolled on through 2021, an opportunistic and deadly fungal infection has been creeping into healthcare and subacute facilities with increasing frequency and resistance.

In 2009 in Japan, Candida auris was first identified; though its exact origins are uncertain, as standard microbiology laboratory methods may lead to misidentification of the organism.  A retrospective study identified strains of the organism as early as 1996 (1). Attributable mortality estimates vary widely, ranging from 22% to 57% in the United States, though a recent analysis suggested a 30-day mortality incidence as low as 17% (2). Between June 1, 2020, and May 31, 2021, 1,012 clinical cases in 20 U.S. states were reported, with four states (California, Florida, Illinois, and New York) reporting more than 100 cases (3). The organism is notifiable nationally since 2018 (4).

The increasing number of reported cases is not the only concern. In a July 2021, report in the Morbidity and Mortality Weekly Report (MMWR), the authors described two distinct clusters in Texas’s acute and long-term care facilities and a long-term care facility in Washington D.C. All isolates described in this report were resistant to multiple antifungal drugs. Five cases between the two localities were pan-resistant or resistant to all known therapeutic antifungal agents available. The overlapping healthcare exposures in these independent clusters in each locale suggest transmission. (5) Resistance traditionally increases the likelihood of treatment failure and death. In these clusters, the 30-day mortality frequency among patients was 30%.

The inflammatory response and necessary medical interventions to infection with SARS-CoV-2 are thought to predispose COVID-19 infected patients to fungal infections, perhaps especially C. auris (6). This coincides with increased reports of outbreaks and public health reports at the state and regional levels. Thankfully, increased antifungal resistance has not had any reported correlations with increased tolerance to disinfectants.  There is little evidence that commonly used disinfectants, even with other Candida species claims, may be less effective against C. auris (7).

Recently, the Centers for Disease Control and Prevention (CDC) updated their recommendations for healthcare professionals with regard to surveillance and infection prevention activities to prevent transmission of C. auris. Concerning surveillance, the CDC recommends screening 1) close healthcare contacts of patients with newly identified infection or colonization 2) patients with overnight healthcare stays outside the United States in the past year-especially in countries with high incidence (though now it has become so widespread that this recommendation is less nuanced) and 3) point prevalence screening in areas of high incidence or suggested transmission (8). Screening sites include the groin and bilateral axilla.

With regard to infection prevention, the CDC has updated its recommendations periodically as recently as July 2021 (9). For environmental surface disinfection, the CDC recommends the use of products on the Environmental Protection Agency’s List P: Antimicrobial Products Registered with EPA for Claims Against Candida Auris. (11). The previous recommendation was to use disinfectants with sporicidal activity on List K: EPA’s Registered Antimicrobial Products Effective Against Clostridium difficile Spores (9, 10). If List P products are not available, List K products may be used. Currently, Sani-Cloth® Prime spray and wipes (EPA registration numbers 9480-10 and 9480-12), Sani-Cloth® HyPerCide spray and wipes (9480-14 and 9480-16) are on List P.  Sani-Cloth® Super wipes (9480-4) has received EPA approval for its claim against Candida auris.  It will be included on List P, though the list is pending an update as of August 30, 2021 (12).

While Candida auris is a relatively new epidemiologically significant HAI pathogen and there are some unique aspects of this organism, the risk of transmission and therefore fundamentals for prevention remain the same. Environmental contamination with this organism increases the risk of infection. With the pandemic showing limited signs of relenting, the increased risk to patients for infection with C. auris means now is the time to double down on efforts to prevent intra-facility transmission.