A Deadly, Drug-Resistant Fungus Threatens People Around the World, Scientists Warn

A deadly, drug-resistant fungus is extending its tendrils around the world. Research out this month finds that the public health threat of Candida auris has steadily climbed over time.

Researchers reviewed the scientific literature on C. auris, which was only discovered in 2009. Since then, outbreaks of the fungus have been reported across the globe, including in the U.S. The infection is often mistaken for other germs and is hard to treat with existing drugs, the researchers add, further raising its danger.

“Taken together, these data underscore the need to develop novel antifungal agents with broad-spectrum activity against human fungal pathogens, to improve diagnostic tests, and to develop immune- and vaccine-based adjunct modalities for the treatment of high-risk patients,” the authors wrote in their paper, published in the journal Microbiology and Molecular Biology Reviews.

The rising fungal menace

Fungal infections have become a growing threat to humanity. A study last year, for instance, estimated that fungi plays a role in killing nearly 4 million people annually, almost double the amount estimated a decade ago. But C. auris—first discovered inside a person’s ear by doctors in Japan in 2009—might be one of the scarier fungi around.

C. auris can colonize our skin without causing any problems. But sometimes, especially in people with weakened immune systems, it will cause a serious, widespread infection that quickly turns life-threatening. About one-third of people hospitalized with C. auris will die from it, research has found, while the mortality rate for bloodstream infections can reach nearly 50%.

One major reason why C. auris is so dangerous is that, compared to other disease-causing Candida species, it’s uniquely adept at resisting many of the most common medications used to treat fungal infections. There have even been recorded cases of pan-resistant C. auris: strains that resist all four major classes of antifungals. To make things worse, conventional tests will regularly misidentify C. auris as other Candida species, which can then lead to delayed or incorrect treatment.

C. auris is still a relatively rare source of fungal illness, but its global burden has clearly been increasing over time, the study researchers note. It’s now been documented in over 50 countries. In the U.S., C. auris infections in hospitals and other healthcare settings have been reported in at least 39 states, with more than 4,500 cases in 2023 (the last year with available data).

On a more existentially frightening level, C. auris might be one of the first emerging diseases directly caused by climate change, the researchers say. Evidence suggests that the fungus only started regularly sickening humans after it adapted to increasingly warmer temperatures—the same sort of temperatures found in our bodies.

Not all hope is lost

Dire as the outlook might seem, there are still reasons for optimism.

The researchers point out that scientists are working on new antifungals, and three promising drugs are far along in development. In 2023, the FDA approved Rezafungin for invasive Candida infections. There’s also been some progress on vaccines, some of which could provide protection against a wide range of fungal pathogens.

The researchers aren’t just highlighting what we’ve learned so far about C. auris; they’re hoping to make the discoveries that will help us fend off these dangerous germs.

“My laboratory investigates how fungal pathogens interact with the host to drive infection, with the goal of uncovering the molecular mechanisms that enable these organisms to cause disease,” study author Neeraj Chauhan, a professor at the Center for Discovery and Innovation at Hackensack Meridian Health in New Jersey, told Gizmodo. “The long-term goal of research is to guide the development of new strategies for diagnosing, preventing, and treating drug-resistant fungal infections.”

With any luck, scientists like Chauhan will find the weaknesses of C. auris long before we end up reenacting fungal nightmare scenarios like The Last of Us.