Colonization by Candida auris in critically ill patients: role of cutaneous and rectal localization during an outbreak

Background: Candida auris infections have been reported worldwide since the pathogen was isolated in 2009. Aim: To analyse the incidence of cutaneous and intestinal colonization, and connection with infections by the organism, in a hospital setting of a C. auris epidemic. Methods: This was a retrospective study in intensive care units (ICUs) at a 1200-bed Italian hospital. The incidence of cutaneous positive swabs, and cutaneous carriers, for C. auris was compared to that of rectal positive swabs, and intestinal carriers, and both were correlated with C. auris infections. Findings: A total of 399 patients were included. Seventy-seven patients were infected by C. auris. The ratio of C. auris positive skin swabs from screening in ICUs was 24%. The ratio obtained from infected patients and intestinal C. auris carriers was 49.1%, likewise rectal swabs from a similar cohort of patients (P = 0.373). Of this cohort, 39.7% and 5.5% were colonized only in skin and in rectum, respectively, while 54.8% was colonized in both sites. Of skin swabs, 12.3% and 83.6%, respectively, were always positive and variable over time in single subjects, while 31.5% and 41.1% of rectal swabs were always positive and variable (P = 0.000). Intestinal colonization was associated with increased risk for C. auris urinary infections (P = 0.006). Conclusion: C. auris intestinal carriers were fewer than cutaneous carriers, but more continuously colonized. Rectal and skin swabs can be good tools for surveillance, respectively, of colonization and of hygiene measures effectiveness. Urinary tract infections by C. auris appeared to increase along with gastrointestinal presence of the yeast.