A new UNLV-led wastewater surveillance study brings scientists one step closer to the global race to identify and prevent skyrocketing cases of a potentially deadly drug-resistant fungus that puts hospital patients at risk of serious infections of the blood, heart or brain.
Candida auris presents ongoing challenges for Nevada health care facilities. In 2025, the Silver State alone accounted for 22 percent of the nearly 7,200 C. auris cases – reporting 1,605 infections to the Centers for Disease Control and Prevention and surpassing California’s roughly 1,550 cases and Texas’ 830. When adjusted for population, Nevada recorded 20 times more cases per capita than its coastal neighbor.
UNLV-led research published in 2023 was the first to demonstrate the effectiveness of using sewer surveillance to detect C. auris in untreated sewage pumped from a sewage treatment plant. And now, the university — in collaboration with the Southern Nevada Water Authority, Southern Nevada Health District, Auburn University, Nevada State Public Health Laboratory at University of Nevada, Reno, and several local water utilities — has built on that groundwork with an online-first study to be published in Nature communications.
The new paper reveals that sampling raw sewage closer to the source – sewer lines that directly serve hospitals, nursing homes and long-term care facilities where C. auris Outbreaks tend to build up and pose the biggest risk to public health – allowing scientists to detect drug-resistant strains of the pathogen up to five months before patients start showing symptoms.
These findings open a new frontier for hospitals, which will no longer have to rely solely on indications in clinical records or on ad hoc testing of people who are already ill.”
Edwin Oh, study co-author, professor and director, Center for Water Intelligence and Community Health, UNLV
“Wastewater surveillance provides a non-invasive biopsy of a hospital community at a facility scale. And we can get answers on a daily basis, paving the way for healthcare facilities to save lives by identifying earlier when pathogens resistant to a standard course of antifungal therapy are present,” Oh continued. “When you complement surveillance with clinical trials, you can detect drug-resistant pathogens months earlier and give clinicians the window they need to change course before an epidemic begins.”
C. aurisalso known as Candidozyma aurisis a fungus that can cause serious wound, bloodstream or organ infections – especially in patients who are immunocompromised, have pre-existing health conditions, are in long-term healthcare or are being treated with invasive medical devices such as a catheter. C. auris does not pose a risk to drinking water systems, but infection prevention and control in healthcare facilities is challenging because the fungus can grow on both dry and wet surfaces, such as furniture, doorknobs, clothing and medical equipment. It has also shown resistance to many surface disinfectants commonly used in all three types of antifungal drugs. More than 1 in 3 patients with invasive C. auris infections die.
With Nevada having the largest on record C. auris outbreak in US history by 2022, scientists say their efforts to eradicate the fungus are critical.
Their Nature communications The study compared untreated wastewater drawn from central municipal wastewater treatment facilities with higher-resolution samples from sewer lines serving three major Southern Nevada hospitals between 2021 and 2024. And they called the results “impressive”: Sewage taken directly from hospital sewers yielded C. auris concentrations nearly 100 times higher than community sewage treatment plants, with detection rates of 95% versus 18%.
The study also revealed unexpected biological insights into how the fungus adapts to drug pressure. The resistant strains showed signs of metabolic rewiring and new stress response mechanisms that could lead to new therapeutic targets.
“Since 2020, wastewater surveillance has proven extremely valuable in understanding the community transmission of diseases such as COVID-19 and influenza,” said study co-author Daniel Gerrity, principal scientist at the Southern Nevada lab. “These new results highlight the benefits of applying this emerging public health tool closer to healthcare facilities, potentially guiding medical professionals to more effective treatment options for their patients.”
The research team collected the data in the construction of one of the largest in the world C. auris repositories. And the next step is to combine genomes with molecular tools and begin developing new antifungal therapeutics—and perhaps even a vaccine that fends off these drug-resistant pathogens.
“Very often, the patient’s own illness is the first signal that a drug-resistant strain has reached a facility, and by then it may have already spread,” said study co-leader Ching-Lan (Lanie) Chang, a neuroscience doctoral student at UNLV. “Wastewater surveillance changes that timeline, giving healthcare workers, patients and their families a head start that simply didn’t exist before. New antifungal treatments and a vaccine remain long-term goals, but the genomic repository we’ve created from this work sets the stage. Meanwhile, wastewater intelligence enables us to act now.”
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