Deadly Fungus Outbreak, What It Is and How to Protect Yourself

Quick Answer

Candida auris is a drug-resistant fungus that has become one of the most urgent infection control challenges in modern health care. In 2025, the CDC reported over 7,000 clinical cases of C.

auris across U.S. health care facilities, with infections spreading to at least 27 states and identified in more than 60 countries worldwide.

The fungus primarily affects people in hospitals and nursing homes, particularly those with weakened immune systems or invasive medical devices, and it resists most standard antifungal treatments. Protection focuses on rigorous hand hygiene, thorough environmental cleaning in health care settings, and early screening of at-risk patients.

Key Facts

More than 7,000 clinical cases of Candida auris were reported in the United States in 2025, according to CDC tracking.
The fungus has been identified in at least 60 countries and in 27 U.S. states during 2025.
Kansas, Kentucky, Mississippi, and Tennessee recorded their first-ever cases during 2025, joining 17 other states already tracking the fungus.
CDC data shows 6,304 new clinical cases of C. auris in the United States in 2024, with the total increasing every year since the first U.S. case in 2016.
A broader CDC surveillance report covering 2022–2024 documented 13,507 clinical cases total, rising from 2,882 in 2022 to 4,428 in 2023 and 6,197 in 2024.
The fungus is resistant to multiple antifungal drugs, making infections difficult to treat and containment especially challenging.
In December 2025, scientists at the University of Exeter reported finding a potential weakness in the fungus related to its ability to acquire iron, opening a new avenue for treatment research.
An outbreak in an Illinois burn intensive care unit from 2021–2023 resulted in 28 patients colonized or infected over two years, illustrating how quickly the fungus can spread in high-risk units.
C. auris can colonize patients without causing illness, and a CDC analysis of 21,195 patients who screened positive for colonization found that some later developed clinical infections.
The WHO has flagged the rising prevalence of fungal disease and antifungal resistance as a growing global concern requiring urgent action.

Why This Fungus Is Different From Other Hospital Infections

Candida auris does not behave like most other hospital-acquired infections, and understanding what makes it unique helps explain why health officials are alarmed.

A Yeast That Behaves Like a Bacterial Superbug

Most people are familiar with Candida albicans, a common yeast that causes vaginal yeast infections and oral thrush. C.

auris is a different species entirely, and its behavior in health care settings is far more concerning. Unlike many fungi that primarily affect people with severely compromised immune systems, C.

auris spreads readily between patients in hospitals and nursing homes, similar to how MRSA or other bacterial superbugs spread. The fungus survives on surfaces for extended periods, resists standard disinfectants, and can persist in health care environments despite routine cleaning.

It has been found on bed rails, chairs, doorknobs, medical equipment, and other high-touch surfaces. This environmental persistence, combined with its drug resistance, makes outbreaks difficult to stop once they begin.

The Colonization Problem

One of the most challenging aspects of C. auris is its ability to colonize patients without causing active infection.

Colonization means the fungus is present on or in the body—commonly on the skin, particularly in the armpit and groin areas—but is not causing symptoms. A CDC analysis of national data from 2016 through 2023 examined 21,195 patients who tested positive for C.

auris on a screening swab. Some of these patients later progressed to clinical case status, meaning they developed an active infection requiring treatment.

This colonization creates an invisible reservoir of the fungus within health care facilities. Patients may be admitted for unrelated conditions, unknowingly carrying C.

auris on their skin, and the fungus can then spread to other patients through contact with health care workers, shared equipment, or contaminated surfaces. Screening swabs, particularly of the axilla and groin, are used to identify colonized patients so that infection control measures can be implemented.

Who Is Most at Risk

Healthy individuals are not considered at risk for C. auris infection.

The fungus targets specific populations:

Patients in intensive care units, particularly those on ventilators
People with central venous catheters or feeding tubes
Patients in long-term care facilities and nursing homes
Individuals with weakened immune systems
Patients who have undergone surgery, particularly burns or complex procedures
People with diabetes or other chronic conditions that increase infection risk

The burn intensive care unit outbreak in Illinois from 2021 to 2023 demonstrates how devastating the fungus can be in high-risk settings. Over two years, 28 patients in that single unit became colonized or infected, requiring extensive infection control interventions to bring the outbreak under control.

The Spread From Rare Fungus to Global Threat

The trajectory of Candida auris from a little-known pathogen to a global health concern has been remarkably fast, and the data shows no signs of the trend reversing.

How the Numbers Have Climbed

The first U.S. case of C.

auris was reported in 2016. From that point, clinical cases increased every single year.

CDC surveillance data shows the escalation clearly:

2022: 2,882 clinical cases
2023: 4,428 clinical cases
2024: 6,197 clinical cases (a separate CDC page cites 6,304)
2025: More than 7,000 clinical cases, with the year's data still being finalized

Between 2022 and 2024 alone, a total of 13,507 clinical cases were reported to the CDC. The increases between years have been substantial, and health officials have described the growth as an urgent threat.

Geographic Expansion

In August 2025, The Hill reported that Kansas, Kentucky, Mississippi, and Tennessee had recorded their first cases of C. auris, joining 17 other states that were already tracking the fungus's spread.

By the end of 2025, more than half of U.S. states had reported clinical cases, with data missing for Alabama and Florida at the time of reporting.

The spread is not limited to the United States. The fungus has been identified in at least 60 countries worldwide.

In Europe, the ECDC reported that Spain, Greece, Italy, Romania, and Germany have accounted for the majority of cases over the past decade. In 2023, the fungus was found in 18 European countries, and several countries have reported ongoing local transmission.

Why It Keeps Spreading

Several factors explain why C. auris continues to expand its geographic reach:

Global travel and health care mobility. Patients are frequently transferred between facilities—from hospitals to nursing homes, between hospitals, and across international borders.

Each transfer creates an opportunity for the fungus to move to a new setting. Difficulty in identification. C.

auris can be misidentified as other Candida species by standard laboratory methods, delaying appropriate infection control responses. Specialized testing is required for accurate identification.

Drug resistance. The fungus is resistant to multiple classes of antifungal drugs, and some strains are resistant to all major antifungal treatments. This resistance makes infected patients harder to treat and prolongs the period during which they can transmit the fungus.

Long-term colonization. Patients can remain colonized for extended periods, even after discharge, creating ongoing transmission risk in long-term care facilities where many colonized patients may reside together.

The Research Breakthrough Finding a Weakness

In late 2025, scientists at the University of Exeter announced a discovery that could change how C. auris is treated.

The Iron Connection

The research team identified a potential weakness in the fungus related to how it acquires iron. Like all living organisms, C.

auris requires iron to survive and grow. The fungus produces molecules called siderophores—essentially iron-capturing compounds—that scavenge iron from the environment and from the human body during infection.

The scientists found that C. auris relies on a specific transport mechanism to bring these iron-laden siderophores into its cells.

This transport system appears to be a vulnerability. If the fungus cannot acquire iron, it cannot proliferate effectively, potentially rendering it susceptible to treatment or preventing infection from establishing in the first place.

The journal reference for this work, published in December 2025, focuses on "Xenosiderophore transport" in C. auris—the process by which the fungus captures and imports iron compounds from its surroundings.

This mechanism differs from how many other fungi acquire iron, making it a potentially specific target for new drugs.

Why This Matters

Current antifungal drugs are limited, and resistance is widespread. Echinocandins are typically the first-line treatment for C.

auris infections, but resistance to these drugs has been documented, and some strains are resistant to multiple drug classes. The mortality rate for invasive C.

auris infections is high, partly because treatment options are so constrained. A drug that targets the iron acquisition system would represent a fundamentally different approach to treating C.

auris. Rather than trying to kill the fungus directly with antifungal compounds, such a drug could starve the fungus of a nutrient it cannot live without.

This approach could potentially be effective against drug-resistant strains because it targets a different biological process than existing antifungals.

The Research Pipeline

The University of Exeter findings are at the research stage, and no new treatment has been developed or approved based on this discovery. The path from laboratory discovery to clinical treatment typically takes years, requiring animal studies, human trials, and regulatory approval.

However, the discovery is significant because it gives researchers a specific molecular target to work toward. Other research has also explored natural compounds from plants that inhibit the growth of drug-resistant Candida fungi, including C.

auris, suggesting multiple avenues of investigation are underway. Health officials and researchers have emphasized that better drugs and better diagnostics are both urgently needed.

Better diagnostics would allow faster identification of C. auris infections, enabling earlier treatment and more effective infection control.

Better drugs would address the growing problem of antifungal resistance, which affects not just C. auris but other fungal pathogens as well.

Practical Protection What Patients and Families Can Do

While the spread of C. auris is primarily a health care facility issue, there are practical steps that patients, families, and visitors can take to reduce risk.

Questions to Ask in Health Care Settings

When a loved one is admitted to a hospital or nursing home, it is reasonable to ask about infection control practices. Useful questions include:

Has the facility had any C. auris cases or outbreaks?
What screening procedures are in place for high-risk patients?
What isolation precautions are used for patients known to be colonized or infected?
How is equipment cleaned between patients?

These questions are not confrontational; they signal that the family is aware of infection risks and expects rigorous practices.

The Power of Hand Hygiene

Hand hygiene remains the single most important infection control measure. Visitors should wash their hands thoroughly with soap and water or use alcohol-based hand sanitizer before and after visiting a patient.

Health care workers should be expected to do the same, and patients or families should not hesitate to remind staff to clean their hands. Alcohol-based sanitizers are generally effective against C.

auris, but soap and water are particularly important when hands are visibly soiled. In outbreak situations, facilities may intensify hand hygiene protocols, and visitors should follow all posted guidance.

What to Know About Isolation Precautions

Patients who are colonized or infected with C. auris may be placed in single rooms with dedicated equipment.

Visitors may be asked to wear gowns and gloves. These precautions are not punitive; they are designed to prevent the fungus from spreading to other vulnerable patients.

Families should understand that isolation is temporary and that it protects other patients who may be far more vulnerable to infection. Cooperating with isolation protocols is one of the most effective ways to help stop the spread.

Understanding Screening

Some high-risk patients may be screened for C. auris colonization using swabs of the armpit and groin.

This screening identifies patients who carry the fungus but have no symptoms. The goal is to implement precautions before transmission occurs.

Screening programs are most common in facilities that have experienced cases or in units where the fungus has been identified. Patients who test positive for colonization may not require treatment—colonization does not always progress to infection—but they will need careful monitoring and appropriate precautions.

The Limits of Individual Action

It is important to be honest about what individuals can and cannot control. C.

auris is primarily a health care-associated infection. Individuals cannot realistically prevent their own exposure by personal actions alone; the responsibility lies heavily on health care facilities to maintain rigorous infection control.

What individuals can do is be informed, ask questions, practice good hand hygiene, and advocate for their own safety and the safety of their loved ones. For the broader population without health care exposure, the risk of C.

auris infection is minimal.

The Bigger Picture Antifungal Resistance as a Systemic Problem

C. auris is not an isolated problem; it is a symptom of a larger crisis in antifungal resistance.

The Agricultural Connection

The use of antifungal drugs in agriculture may be contributing to resistance in infectious yeasts, according to related research. Antifungals are widely used to protect crops from fungal diseases, and these same drug classes are used in human medicine.

The environmental presence of antifungals can drive resistance in fungi that are also human pathogens, including Candida species. This agricultural connection is particularly concerning because it means resistance can emerge in the environment, not just in health care settings.

A fungus that develops resistance in a field can eventually find its way into a hospital, bringing that resistance with it.

The WHO Warning

The World Health Organization has highlighted the need for better drugs and better diagnostics for deadly fungal infections. The WHO's concern extends beyond C.

auris to include other fungal pathogens, such as Aspergillus species, which cause serious lung infections, particularly in immunocompromised patients. The global antifungal pipeline is thin.

Developing new antifungal drugs is scientifically challenging because fungi are eukaryotic organisms, like humans, meaning that drugs that kill fungi can also harm human cells. This is different from antibiotics, which target bacteria—organisms that are fundamentally different from human cells.

Why Fungal Threats Are Growing

Several factors are driving the growth of fungal infections globally:

An aging population with more chronic diseases. More people are living with conditions that weaken the immune system or require medical interventions that increase infection risk. More invasive medical procedures. Ventilators, central lines, and other devices create entry points for infections and provide surfaces for fungi to colonize.

Climate change. Some researchers have suggested that rising temperatures may be selecting for fungi that can survive at human body temperature, potentially expanding the range of fungal pathogens. Global health care connectivity. Patients move between facilities and countries more than ever, spreading pathogens across borders.

What Needs to Change

Addressing the antifungal resistance crisis requires multiple approaches:

Better surveillance. Continued tracking of C. auris and other fungal pathogens is essential to understand where they are spreading and how fast.

Better diagnostics. Currently, fungal infections can be difficult to diagnose quickly and accurately. Faster diagnostics would enable earlier treatment and better infection control.

New drugs. The discovery of the iron transport vulnerability in C. auris is one example of the kind of basic research needed to develop new treatment approaches.

The WHO has called for increased investment in antifungal drug development. Stewardship of existing drugs. Using existing antifungal drugs more carefully can slow the development of resistance.

Infection control. Rigorous infection control in health care settings remains the first line of defense against C. auris and other health care-associated pathogens.

Frequently Asked Questions

What is Candida auris and why is it dangerous?

Candida auris is a species of yeast that causes severe infections, primarily in health care settings. It is dangerous for two main reasons: it is often resistant to multiple antifungal drugs, making infections hard to treat, and it spreads readily between patients in hospitals and nursing homes.

It can also survive on surfaces for long periods, making it difficult to eliminate from health care environments.

How is Candida auris transmitted?

C. auris is transmitted through contact with contaminated surfaces, shared medical equipment, or health care workers' hands.

Patients can also carry the fungus on their skin without showing symptoms (colonization), and this can spread to other patients. It is not transmitted through the air like some respiratory infections.

Who is most at risk of getting infected?

The fungus mainly affects people already in health care facilities, particularly those in intensive care units, people with invasive medical devices like ventilators or central lines, patients in nursing homes, and individuals with weakened immune systems. Healthy people outside of health care settings are not considered at significant risk.

Can Candida auris be treated?

Yes, but treatment is difficult because of drug resistance. Echinocandins are typically the first-line treatment, but resistance to these drugs has been documented, and some strains are resistant to multiple antifungal classes.

New treatments are being researched, including approaches that target the fungus's iron acquisition system, but these are not yet available.

What should I do if a family member is in a hospital with a C. auris outbreak?

Ask hospital staff about the precautions in place, practice rigorous hand hygiene before and after visiting, follow all isolation protocols, and cooperate with any screening procedures. Families should also understand that isolation precautions protect the patient and other vulnerable individuals.

If staff appear not to be following hand hygiene protocols, it is appropriate to ask them to clean their hands.

Reference Notes

Information in this article is based on publicly available sources. Some details may change over time.

Verify with official sources before acting. Key sources referenced include CDC surveillance reports and tracking pages for C.

auris, the MMWR surveillance summary for 2022–2024, the University of Exeter research announcement published via ScienceDaily in December 2025, the CDC Emerging Infectious Diseases journal articles on C. auris epidemiology, and contemporaneous news reporting from The Hill, Los Angeles Times, CBS New York, Fox News, and PEOPLE magazine.

Case counts cited in this article come from CDC reports and may be updated as surveillance continues. The 2025 case total is based on partial-year data reported by CDC and news sources; final figures may differ.

The University of Exeter research on the iron transport weakness is at the laboratory stage, and no treatment based on this discovery is currently available.

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