LAUSR

What is unique about Candida auris? The emerging fungal pathogen Candida auris is causing outbreaks of invasive disease in healthcare facilities around the world [1–4]. Isolates often exhibit resistance to multiple drug classes, and invasive disease carries an astonishingly high mortality rate, approaching 60% [5]. The initial description of C. auris arose following the isolation of a novel species from the ear canal of a patient in a Japanese hospital [2]. Since this report in 2009, cases have subsequently appeared in hospitals in South Korea, India, the Middle East, South Africa, and South America [6–10]. More recent reports reveal the spread of C. auris to North American and European healthcare facilities [3, 11]. Genomic analysis shows that the circulating strains cluster into distinct clades, which appear to have emerged independently [5]. Retrospective analyses of Candida isolates collected from international sites in the decades leading to 2009 uncovered only rare cases of C. auris, confirming the recent emergence of this species [5, 10]. C. auris is the first fungal pathogen categorized as a public health threat due to its ability to readily colonize skin, spread rapidly among patients, and cause severe disease [3–5, 12]. The efficient person-to-person transmission observed for C. auris is striking, because candidiasis caused by other species typically arises from the patient’s own microbiome, often from the gastrointestinal tract. However, unlike other Candida spp., C. auris does not appear to efficiently colonize the gastrointestinal tract, presumably due to its poor growth under anaerobic conditions [13]. An additional factor contributing to the spread of C. auris is the propensity of the species to persist on the surfaces of hospital rooms and on medical devices [14, 15]. With these barriers to nosocomial control, C. auris continues to spread. In an area where it first emerged, C. auris now accounts for nearly 20% of Candida bloodstream isolates, surpassing that of C. albicans, which is typically the most common species [16].