A potentially fatal, drug-resistant fungal infection is becoming increasingly common in Texas hospitals. One of San Antonio’s largest hospitals has implemented protocols to screen for the microbe.
Candida auris (C. auris) is a yeast that can cause severe infections in humans.
Although it’s not a concern for most healthy people, the fungus poses a risk to immunocompromised patients at hospitals and long-term care facilities like nursing homes, especially those hooked up to invasive medical devices like breathing tubes or catheters, which offer pathways for the fungus into the body.
Texas is a C. auris hotspot. The state has recorded 437 clinical cases so far in 2026, second only to California, according to the U.S. Centers for Disease Control and Prevention, though these data are preliminary.
University Hospital in the South Texas Medical Center has recorded 30 cases since 2023, prompting officials to establish surveillance protocols to prevent outbreaks.
“The numbers aren’t huge,” said Jason Bowling, University Health’s chief epidemiologist. “But we are seeing those numbers from 2023 to 2026 start to increase.”
According to Nathan Wiederhold, director of UT Health San Antonio’s fungus testing laboratory, C. auris is concerning for three main reasons.
It’s difficult to detect with common diagnostics, which often don’t differentiate between benign species of candida and C. auris. It sticks around on surfaces, like bed railing, tables, medical equipment for long periods, and is immune to some common disinfectants. And it’s drug resistant, with some strains able to outmaneuver all of the antifungal drugs thrown at it, a problem that will likely get worse without new treatments.
“We’re starting to run out of options,” Wiederhold said. “We’re afraid that in the future, these infections are going to be even more difficult to treat as resistance continues to develop.”
A global health priority
C. auris is a species of the Candida genus, a common group of yeast that includes many microbes that usually live happily on our skin and inside our bodies.
Overgrowth of these microbes can cause problems, however. Thrush, vaginal yeast infections and some kinds of rashes, for example, are the result of too many of these microbes.
While scientists have known about Candida fungi for many decades, C. auris is relatively new. The fungus was first described by Japanese doctors in 2009.
Initially, “no one thought anything of it,” Wiederhold said, until doctors started finding that it could cause life-threatening bloodstream infections.
Some researchers have suggested that C. auris could be the result of climate change and rising global temperatures, which the fungus seems to thrive in. It would be the first known case of a pathogen emerging as the direct result of man-made climate change. But such connections are difficult to prove.
The CDC first reported its presence in the U.S. in 2016. Since then, the fungus has been found in almost every state, Wiederhold said. The number of annual clinical cases rose from roughly 1,500 in 2021 to over 6,000 in 2024, according to CDC data.
Not all of these cases are active infections. Rather, they also include what doctors refer to as “colonization,” which means someone is carrying the fungus (and likely spreading it) without any symptoms.
“This really reflects the challenge with this pathogen,” Bowling said. “A lot of people can carry this without knowing,” including healthcare workers.
The rate of increase in cases does seem to be slowing. And at least some of the increase could be attributed to better surveillance, Wiederhold said.
The World Health Organization has classified the fungus as a “critical priority” and one of 19 fungi that pose a risk to global health.
Part of the reason the fungus is of particular concern is its resistance to antifungal medications. Antimicrobial resistance — which arises when microbes adapt to evade the effects of medications designed to kill them — is growing worldwide.
Most strains of C. auris are resistant to at least one antifungal medication, but will respond to a class of medications called echinocandins. Some strains, however, are resistant to all classes of antifungal medications, making it difficult and in some cases impossible to treat. A promising new antifungal aimed at C. auris is in phase three clinical trials, Wiederhold said.
On the frontlines
There’s no common set of symptoms associated with C. auris since they depend on where the fungus is present in the body. It can resemble a typical bacterial infection, cause a minor rash or become life threatening if present in the bloodstream.
University Hospital has started screening patients being transferred from long-term care facilities who have been hooked up to invasive medical devices, and anyone in the hospital who tests positive for the fungus is isolated. The hospital has also transitioned to disinfectants that can kill the fungus, Bowling said.
“Most of the cases that we’ve detected have been in cultures that we’ve obtained when people are being admitted, particularly when they’re coming from long-term care, like a long-term care acute care hospital or a skilled nursing facility, like a nursing home,” Bowling said.
Only a handful of their 30 cases over the last three and a half years, when they first detected it, have resulted in serious infections. Bowling said that they did have a few cases of serious bloodstream infections, and that he wasn’t aware of any fatalities, though that can be difficult to determine based on the condition of these patients.
Because most patients who get sick from C. auris were already quite ill, it’s hard to know whether the fungus or the underlying condition caused their death. So it’s difficult to parse out fatalities.
One 2023 paper found that the mortality rate from C. auris bloodstream infections could be between 30 and 60%, which is significantly high for a fungus, Wiederhold noted. The CDC estimates a mortality rate of 47% for bloodstream infections.
Part of Wiederhold’s job is ensuring physicians and health systems are aware of the fungus. Many doctors simply do not have C. auris in their differential diagnosis, he said, and hospitals and long-term care facilities will need to implement protocols to protect patients from outbreaks.
“Some institutions are prepared,” Wiederhold said, “but there are probably some institutions where it’s not been on their radar, and they’re not as prepared as others.”
