Candida auris Outbreak and Epidemiologic Response in Burn Intensive Care Unit, Illinois, United States, 2021–2023

Abstract

Candida auris is an emerging fungal pathogen associated with outbreaks in healthcare settings. We report a multiyear outbreak of C. auris in a burn intensive care unit in Illinois, USA, during 2021–2023. We identified 28 C. auris cases in the unit over a 2-year period, despite outbreak response and multimodal mitigation measures. Of the 28 case-patients, 15 (53.6%) were considered colonized and 13 (46.4%) had clinical infections. Phylogenetic analysis of whole-genome sequences revealed 4 distinct clusters of closely related (0–6 SNP differences) genomes containing 3–6 cases. Clusters generally contained temporally related isolates from patients with epidemiologic links; this finding suggests that multiple introductions and within-unit spread over a limited time were responsible for the outbreak, rather than transmission from a long-term source (e.g., persistent environmental contamination or staff carriage). Here, integrated traditional and genomic epidemiology supported C. auris outbreak investigation and response and informed targeted interventions.