Community-Scale Wastewater Surveillance of Candida auris during an Ongoing Outbreak in Southern Nevada

Abstract

Candida auris is an opportunistic fungal pathogen and an emerging global public health threat, given its high mortality among infected individuals, antifungal resistance, and persistence in healthcare environments. This study explored the applicability of wastewater surveillance for C. auris in a metropolitan area with reported outbreaks across multiple healthcare facilities. Influent or primary effluent samples were collected over 10 weeks from seven sewersheds in Southern Nevada. Pelleted solids were analyzed using an adapted quantitative polymerase chain reaction (qPCR) assay targeting the ITS2 region of the C. auris genome. Positive detection was observed in 72 of 91 samples (79%), with higher detection frequencies in sewersheds serving healthcare facilities involved in the outbreak (94 vs 20% sample positivity). Influent wastewater concentrations ranged from 2.8 to 5.7 log 10 gene copies per liter (gc/L), and primary clarification achieved an average log reduction value (LRV) of 1.24 ± 0.34. Presumptive negative surface water and wastewater controls were non-detect. These results demonstrate that wastewater surveillance may assist in tracking the spread of C. auris and serve as an early warning tool for public health action. These findings provide the foundation for future application of wastewater-based epidemiology (WBE) to community-or facility-level surveillance of C. auris and other high consequence, healthcare-associated infectious agents.

A retrospective longitudinal study of adenovirus group F, norovirus GI and GII, rotavirus, and enterovirus nucleic-acids in wastewater solids at two wastewater treatment plants: Solid-liquid partitioning and relation to clinical testing data

“…Therefore, WBE data can be complementary to clinical data by providing rapid results at a community scale and may even provide early warnings of disease spread. Work to date suggests that wastewater monitoring are related to community disease levels and can be used to detect occurrence of important respiratory 6,7 , enteric 8,9 , and emerging and outbreak infections 10,11 .…”

Observations of Respiratory Syncytial Virus (RSV) Nucleic Acids in Wastewater Solids Across the United States in the 2022–2023 Season: Relationships with RSV Infection Positivity and Hospitalization Rates

“…Until then, however, the clinical data used herein represent the best available publicly accessible RSV data. Lack of complete, reliable population-level clinical data is a challenge for a wide range of important infectious diseases that are being studied using wastewater surveillance. , Scientists in the field of wastewater-based epidemiology will need to continue to develop creative approaches for validating wastewater data when high-quality population-level clinical data do not exist. Collaborations with infectious disease scientists to carry out coupled wastewater-disease surveillance studies in small geographic regions may be one solution.…”

Prospective study ofCandida aurisnucleic-acids in wastewater solids in 190 wastewater treatment plants in the United States suggests widespread occurrence

“…For WWTPs that did not provide a sewershed (n = 75), we approximated sewershed boundaries based on the zip codes serviced by the WWTP and USA ZIP Code Boundaries geospatial data set published by Esri (Source: TomTom, US Postal Service, Esri) (34). We tested whether concentrations measured by the assay presented in Table 1 were different from those measured by the Barber et al assay using RT-ddPCR on 9 representative samples (Table S3, Figure S2) (25). We ran the same samples using RT-ddPCR and ddPCR with no RT step (Table S3, Figure S2).…”