Since January 2021, the Centers for Disease Control and Prevention (CDC) has detected independent clusters of Candida auris, or C. auris, in Texas and Washington, D.C. that are resistant to known antifungal treatments, the agency reported in its Morbidity and Mortality Weekly Report.
Candida auris is an emerging, often multidrug-resistant yeast that is highly transmissible, resulting in healthcare-associated outbreaks, especially in long-term care facilities.
The CDC said that the two simultaneous, independent clusters of resistance to all known antifungal treatments or echinocandin occurred in patients with overlapping inpatient healthcare exposures and without previous echinocandin use — typically the first-line therapy for C. auris. Each cluster involved common healthcare encounters and no known previous echinocandin exposure, suggesting transmission of strains that are either resistant to echinocandin or all known treatments.
Among 101 clinical and screening cases of C. auris in Washington, D.C. during January-April 2021, three had an isolate that was pan-resistant, which means it was resistant to known treatments. All resistant isolates were identified through skin colonization screening at one long-term care facility for severely ill patients, including those requiring mechanical ventilation.
In Texas, during the same period, two out of 22 clinical and screening cases of C. auris were pan-resistant and five were resistant to both echinocandins and fluconazole, another common treatment. These seven cases were identified in patients who were cared for at two facilities that share patients in the same city; two patients were at a long-term acute care hospital, three at a short-term acute care hospital, and two at both facilities. Among these cases, four were identified through colonization screening and three through clinical isolates (two blood isolates and one wound isolate).
No known epidemiologic links were identified between the clusters in Washington, D.C. and Texas. No patients with pan- or echinocandin-resistant isolates in either cluster had received echinocandins before C. auris specimen collection. Thirty-day mortality in both outbreaks combined was 30%, but the relative contribution of C. auris was unclear.
