A drug-resistant fungus is spreading through hospitals, and the CDC calls it urgent

A yeast called Candida auris has become one of the most closely watched pathogens in American hospitals, not because it threatens healthy people but because it thrives in exactly the places where the sickest patients are treated. It resists the drugs meant to kill it, survives for weeks on bedrails and medical equipment, and moves silently from patient to patient in intensive-care units and long-term care facilities. Federal health officials have placed it in their highest tier of concern, a designation reserved for the small number of resistant microbes considered immediate dangers to public health.

What makes the fungus unnerving is the combination of stealth and durability. Many people it colonizes never feel sick, carrying it on their skin while unknowingly spreading it to others, and the organism can persist on surfaces long after a room appears clean. For patients tethered to ventilators, feeding tubes, and central lines, that persistence can turn into a bloodstream infection that is difficult to treat and often deadly.

Why the CDC ranks it an urgent threat

The classification is not rhetorical. The Centers for Disease Control and Prevention has deemed C. auris an urgent antimicrobial resistance threat because it is often resistant to multiple antifungal drugs, spreads easily in healthcare facilities, and can cause severe infections with high death rates. That “urgent” label sits at the top of the agency’s ranking system for resistant pathogens, the same category assigned to a handful of the most dangerous drug-resistant bacteria. The CDC’s Antimicrobial Resistance Threats Report is the document that first identified C. auris as an urgent threat in the United States, grouping it with organisms that demand aggressive and coordinated action to contain.

The World Health Organization has echoed that assessment on a global scale, placing the fungus in the top group of its first-ever list of health-threatening fungi. The agreement between national and international authorities reflects how quickly the organism went from a laboratory curiosity to a recognized hazard in the span of a few years.

A steep climb in cases since 2016

The first U.S. case was reported in 2016, and the trajectory since has been steep. The agency documented a particularly rapid rise in the early 2020s, with clinical cases, meaning infections rather than symptomless carriage, climbing from 476 in 2019 to 1,471 in 2021. Just as alarming, the number of cases resistant to echinocandins, the class of antifungal medicine most recommended for treatment, tripled in 2021. During the 2019 to 2021 stretch, 17 states identified their first-ever case, a sign the fungus was reaching new parts of the country rather than simply intensifying where it already existed.

The growth has continued, even as the pace of increase has eased somewhat from its peak. The CDC reported 6,304 clinical cases in 2024, and notes that the total number of U.S. clinical cases has risen every year since the first was recorded. Officials attribute the increase to several overlapping factors, including gaps in infection-prevention practices, expanded screening that catches more carriers, and the strain the COVID-19 pandemic placed on hospitals, which appears to have worsened transmission during its worst stretches.

How it moves through a hospital

The organism’s spread is a story about surfaces and contact rather than coughs and sneezes. The CDC describes C. auris as highly transmissible between patients through contact with contaminated surfaces or objects, noting that it can shed onto bedrails, doorknobs, and mobile medical equipment and can survive on surfaces for weeks. That endurance makes it stubbornly hard to eliminate through routine cleaning, and the agency recommends thorough daily and terminal disinfection of the rooms of affected patients along with careful cleaning of any shared equipment.

Colonization is central to how it persists. A patient can carry the fungus on the skin and in the nostrils without any symptoms, sometimes for long after an active infection has resolved, and the CDC says there is currently no proven strategy to eliminate that carriage. Because colonized patients look and feel well, they can seed the organism throughout a facility before anyone knows it is present, which is why screening with skin swabs has become a core defensive measure.

Who is at risk and how it is treated

The people most vulnerable are those already gravely ill. The CDC identifies the highest-risk patients as those who require complex medical care, have invasive medical devices such as ventilators or central lines, or endure frequent or prolonged stays in healthcare facilities. People without those risk factors generally do not become infected or colonized, which is why the fungus is a hospital and nursing-home problem rather than a community one. That distinction offers little comfort inside the facilities where the most fragile patients are concentrated.

Treatment is complicated by the resistance that defines the organism. Echinocandins are the recommended first-line therapy for infections in adults, but the CDC reports that echinocandin-resistant and even pan-resistant cases are increasing, and some outbreaks have involved patients who never received antifungal treatment, pointing to direct transmission of already-resistant strains. Accurate identification is its own hurdle, since standard laboratory methods can misidentify the fungus as a different, more familiar yeast, and confirming it requires specialized sequencing or mass spectrometry. The containment strategy that health officials keep returning to is not a new drug but old-fashioned vigilance: early detection, aggressive screening, strict infection control, and thorough environmental cleaning, applied consistently before the organism gains a foothold. Where those measures are put in place early, the CDC says, spread has been slowed, offering a template for facilities racing to stay ahead of a pathogen that has proven it can travel.

This article was produced with AI assistance and reviewed by Morning Overview editors.

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