Seasonal Analysis of Candida auris Detection Rates at 80 Wastewater Monitoring Sites in the United States, December 2023–November 2024

Candida auris is an emerging fungal pathogen known to cause outbreaks in healthcare settings that are difficult to control. Here, data from 80 wastewater treatment plants were collected between December 2023 and November 2024 to compare C. auris seasonal detection rates across the four meteorological seasons. The mean C. auris seasonal detection rate communicated as a percentage (((# of detections per site/# test days per site)/# total sites)*100) was highest in the summer (7%), followed by fall (4%), spring (4%) and winter (2%). A Kruskal–Wallis test identified a significant difference between the seasons (H = 43.6, p < 0.0001) and a Dunn's post hoc test with Bonferroni correction identified pairwise differences between summer and each of the other seasons ( p < 0.05). Statistical significance and 95% confidence intervals (CI) were further assessed by a bootstrapping analysis that also identified a significant difference between summer and all other seasons ( p < 0.01). Proportionally, 39 (48%) sites had their highest seasonal detection rate in summer, followed by 21 (27%) in fall, 15 (18%) in spring and five (7%) in winter. These results collectively document elevated C. auris seasonal detection rates in summer, providing new context to apply C. auris wastewater surveillance.