A team of researchers from Nevada and Utah this week reported the detection of Candida auris in samples from a wastewater treatment plant.
In a dispatch published in Emerging Infectious Diseases, a team led by scientists with the Utah Department of Health and Human Services and the Nevada Department of Health and Human Services described the culture-based recovery of C auris colonies in one of eight samples collected at a wastewater treatment plant in southern Nevada from May 23 to Jun 13, 2022, during an intense outbreak of the multidrug-resistant yeast. Genomic analysis of two separate wastewater-derived C auris isolates revealed phylogenetic relatedness to isolates from three acute-care hospitals in the same watershed.
It remains to be determined whether C. auris could be detected in geographic areas by wastewater surveillance before being recognized in clinical settings.
The first clinical case of C auris in Nevada was identified in June 2021. As of June 2022, a total of 300 C auris cases had been reported in 22 healthcare facilities in Nevada. According to Centers for Disease Control and Prevention tracking data, there were 1,994 clinical cases reported in 28 states from October 2021 to September 2022.
The authors say the findings highlight the potential utility of community-level wastewater surveillance for C auris, which spreads easily in healthcare settings and can cause severe and deadly infections in patients who have compromised immune systems. But they note there are limitations to their methods, which involved growing the culture in the presence of the antifungal fluconazole, which prevented other Candida species from growing. C auris is frequently resistant to fluconazole.
"It remains to be determined whether C. auris could be detected in geographic areas by wastewater surveillance before being recognized in clinical settings," they wrote. "Regardless, wastewater surveillance of pooled samples at the community level might effectively complement clinical surveillance of individual patients for detecting and characterizing C. auris outbreaks."