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Deadly molds (fungi) that “eat you from the inside out” are quickly spreading around the world

by , | Mar 24, 2026 | Mold and Health

It sounds like something scripted for a horror film.

A microscopic organism drifts through the air, finds its way into your lungs, and begins consuming you from the inside out.

No visible wound.

No obvious trauma.

Just a slow, invisible destruction of tissue, organs, and, for millions of people around the globe every year, life itself.

This is not fiction.

Public health authorities from the World Health Organization (WHO) to the U.S. Centers for Disease Control and Prevention (CDC) have sounded the alarm.

Microscopic fungal threats are quietly expanding across the globe, driven by climate change, drug resistance, and decades of underfunding in fungal research.

Mycologists and infectious disease specialists are warning that without urgent action, these organisms could represent one of the most serious emerging health threats of our time.

Some researchers are now calling it a potential modern plague — one that grows in our walls, drifts through our hospitals, and thrives in the warming world we are creating.

In October 2022, the World Health Organization took an unprecedented step: it published the world’s first-ever Fungal Priority Pathogens List (FPPL), placing Aspergillus fumigatus, Candida auris, Candida albicans, and Cryptococcus neoformans in the critical priority group.

The WHO attributes roughly 1.6 million deaths annually to fungal infections, with invasive aspergillosis alone identified as the leading fungal cause of death globally.

The WHO’s decision was driven by data that had long been ignored.

COVID-19 accelerated that already troubling trend dramatically.

According to a landmark study published in Clinical Infectious Diseases, fungal hospitalization rates increased significantly during 2019–2021, and the increase was “primarily driven by hospitalizations of patients with COVID-19–associated fungal infections”.

Fungal infections now cause annual mortality rates approximately equal to tuberculosis and HIV combined.

The CDC’s own publication Emerging Infectious Diseases addressed the question directly in 2024, acknowledging that “a rising percentage of emerging infectious diseases has been fungal in nature, including multidrug-resistant species with considerable mortality such as Candida auris.”

A 2024 PubMed study on invasive fungal infections noted bluntly:

“Fungi were not previously considered a substantial risk to human health, but this perception changed with the rise of the HIV epidemic.” Today, with a far larger immunocompromised population globally, the threat has grown proportionally.

The WHO also acknowledged a dangerous gap in scientific attention, noting that “despite the increasing threat they pose to public health worldwide, fungal infections often receive less funding and attention compared to other diseases.”

This chronic underfunding has left global public health dangerously underprepared.
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A 2022 editorial in Frontiers in Microbiology summarizing the WHO’s findings noted starkly: “Invasive Aspergillus fumigatus is a deadly infection with a 50% mortality rate.”

Meanwhile, Candida auris and Candida albicans “can cause outbreaks with high mortality in healthcare facilities and are resistant to major classes of antifungal drugs.”
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Dr. Hanan Balkhy, WHO’s Assistant Director-General for Antimicrobial Resistance, stated at the release of the FPPL:

“Fungal pathogens are a major threat to public health and yet they are often overlooked. The FPPL is a call to action for governments, researchers, and the pharmaceutical industry to prioritize fungal pathogens and act before the threat worsens.”

A 2018 American Society for Microbiology report noted that “aspergillosis infections have a high mortality rate of about 50% with timely diagnosis and treatment — otherwise the mortality rate is 80%.”

These numbers rival some of the deadliest bacterial pathogens on record.

This is why I’ve been sounding the alarm that we may be living through a modern plague-like situation driven by fungal exposure, toxic mold, misdiagnosis and lack of awareness.

What we’re seeing now is only the tip of a much larger fungal tidal wave affecting people in every country around the world.

And in my view, the real numbers are likely far worse than reported.

As Dr. Arturo Casadevall from Johns Hopkins Bloomberg School of Public Health stated;

“In the near horizon, the prevalence of fungal diseases is likely to increase, as there will be more hosts with impaired immunity and drug resistance will inevitably increase after selection by antifungal drug use. All trends suggest that the importance of fungal diseases will increase in the 21st century.”

Then we have massive misdiagnosis problem around the globe that is only compounding the problem.

Many illnesses that doctors treat every day — like Asthma, Cancer, Dementia, and Alzheimer’s disease — may sometimes be linked to hidden fungal infections or toxic mold exposure but are often misdiagnosed or overlooked as possible mold-related conditions.

This is why awareness is so important right now.

The American Society for Microbiology warned as far back as 2018, in terms that remain urgently relevant today:

“Fungal infections are often difficult to diagnose and treat because the fungi share many biological traits with human cells, making it difficult to develop drugs that target the infection without harming the patient. The situation is further complicated by the increasing prevalence of drug-resistant strains.”
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According to epidemiological research, microbial infection — of which fungal infection is now an acknowledged part — is responsible for initiating an estimated 2.2 million new cancer cases per year globally.

A 2022 review in a peer-reviewed journal provided a comprehensive framework connecting fungal infections to esophageal, gastric, colorectal, lung, cervical, skin, and ovarian cancers, noting that “based on epidemiological evidence, there is a clear link between pathogenic fungal infections and cancer development.”

A 2025 comprehensive review in PubMed synthesizing the current state of the science concluded:

“Cancer-associated fungal populations could be utilized as a target for a combination therapy involving the integration of anticancer and antifungal drugs as well as inhibitors of fungal morphogenesis to develop more effective anticancer therapies.”

The researchers further observed that fungi and cancer cells share a remarkable parallel: “Inhibiting differentiation causes apoptosis in fungi, whereas preventing apoptosis leads to cancer in multicellular organisms.”

As researchers Desai and Thompson stated emphatically on the Issues in Science and Technology, 2025″

“The crisis is deadly serious. A coordinated and collaborative approach between governmental agencies that regulate human and agricultural health and those that prevent environmental degradation is necessary to develop strategies for mitigating antifungal resistance.”

“The scientific and public health communities must coordinate efforts to increase public awareness, boost researchers’ understanding of pathogen spread, and develop comprehensive eradication efforts. Addressing the many health threats related to this complex nexus of anthropogenic factors through collective, cross-disciplinary action must start immediately.”
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What Are The Molds/Fungi Causing Disease and Death?

Aspergillus

Aspergillus fumigatus is a species of mold found almost everywhere on Earth — in soil, compost, dust, and decaying organic matter.

Since 2016, our company Mold Safe Solutions in Southern California has completed more than 3,000 mold inspections for homeowners, landlords, and property managers.

One clear pattern we consistently see is that Aspergillus is usually the most common mold type found in indoor air samples and often has the highest spore counts compared to other molds.

This trend shows up again and again across different property types, including houses, apartments, and commercial buildings.

It releases microscopic spores that are constantly inhaled by humans without consequence for most healthy people. The immune system simply clears them.
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But for the immunocompromised — cancer patients, transplant recipients, people with HIV, those on long-term steroids, or individuals recovering from severe respiratory illness — these spores can take hold in the lungs and begin something far more sinister.

The fungus invades lung tissue, blood vessels, and organs, consuming them in a process that physicians describe as invasive aspergillosis.
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The description “eats you from the inside out” is not hyperbole.

Aspergillus grows as thread-like filaments called hyphae that physically penetrate and destroy tissue.

Without prompt diagnosis and treatment, the infection spreads through the bloodstream to the brain, kidneys, and heart.

Dr. George Thompson from UC Davis Medical Center told CNN (CNN, 2025):

“Aspergillus is ubiquitous — found in your soil, in the leaves you rake, and in the mulch you use. It’s virtually impossible to avoid and has a very high mortality rate — around 40% in certain individuals — making it an infection for which we urgently need new treatments.”
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Researchers at the University of Manchester published landmark modeling research in 2025 mapping how three Aspergillus species — A. fumigatus, A. flavus, and A. niger — would shift their global geographic range under different warming scenarios. The results were alarming.
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Under a severe climate scenario, the spread of A. fumigatus in Europe alone could increase by 77.5%, potentially putting 9 million more people at risk of infection.

A. flavus, which favors warmer tropical climates, could see its range expand by 16% in Europe, threatening an additional 1 million people — while simultaneously spreading into northern China, Russia, Scandinavia, and Alaska.

According to Dr. Norman van Rhijn of the University of Manchester, “We’ve already seen the emergence of the fungus Candida auris due to rising temperatures, but until now, we had little information on how other fungi might respond to this change in the environment.”

He added that fungi remain “relatively under-researched compared to viruses and parasites,” yet these new maps show they will likely “reach most areas of the world in the future.”
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The reason A. fumigatus is particularly dangerous in a warming world relates to a grim biological detail: the fungus thrives at 37°C — precisely the temperature of the human body.

Candida Auris: The Hospital Superbug

While Aspergillus represents the environmental threat, Candida auris is the healthcare nightmare. It spreads rapidly through hospital wards, clings to surfaces and equipment, and is extraordinarily difficult to eliminate.
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A 2025 systematic review and meta-analysis published on PubMed found that the global pooled mortality rate in immunosuppressed patients infected with multidrug-resistant C. auris was 41.5%.

In Tennessee, a 2025 study found that 30.1% of patients with clinical C. auris infections died within 30 days.

C. auris resists most of the antifungal drugs that doctors have available.

A 2025 analysis found a fluconazole resistance rate of 77.42% in studied isolates, with some isolates showing resistance to all known antifungals — so-called pan-resistance.

The CDC has classified it as an urgent antimicrobial resistance threat.
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By the end of 2025, C. auris had spread to more than 27 U.S. states, with over 7,700 confirmed clinical cases reported.

Leading mycologist Dr. Anuradha Chowdhary of the Medical Mycology Unit at the Vallabhbhai Patel Chest Institute, University of Delhi — one of the first scientists to identify C. auris as a major public health threat — and co-author Dr. Neeraj Chauhan of Rutgers New Jersey Medical School wrote in their landmark 2025 global review:

“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. Future efforts should focus on raising awareness about fungal disease through developing better surveillance mechanisms, especially in resource-poor countries.”

Their review also revealed a chilling biological picture:

C. auris can switch from yeast growth to filament-driven spread, forms multicellular aggregates, and attaches “like a kind of glue to mammalian cells — and even non-living surfaces,” making disinfection of hospital rooms extraordinarily difficult.

As average global temperatures rise, regions that were once too cold for the fungus are becoming hospitable environments both outdoors and inside human lungs.

The World Economic Forum noted that “rising global temperatures will accelerate the spread of a fungus responsible for millions of infections and up to 2.5 million deaths globally each year.”

A peer-reviewed climate study published in Thorax in 2025 confirmed that “rising temperatures, changing precipitation patterns and extreme weather events are driving the adaptation of fungal pathogens to new climates, expanding their geographical range and posing a growing threat to human health.”

Candida auris, meanwhile, is a drug-resistant yeast first identified in 2009 in a patient’s ear canal in Japan.

It has now been found in at least 61 countries across six continents, spreading through healthcare facilities with alarming speed.

In 2025 alone, the CDC confirmed 7,702 cases of C. auris across 30 U.S. states.

Melissa Nolan, assistant professor of epidemiology and biostatistics at the University of South Carolina, issued one of the bluntest warnings on record:

“If you get infected with this pathogen that’s resistant to any treatment, there’s no treatment we can give you to help combat it. You’re all on your own.”

A Modern Plague in the Making?</h2?

Are we watching the early stages of a fungal pandemic?

The CDC’s own publication Emerging Infectious Diseases explored this question in 2024, triggered by the cultural phenomenon of HBO’s The Last of Us, which depicted a world destroyed by a weaponized fungal pandemic.

Their conclusion was measured but sobering: while a Cordyceps-style pandemic remains improbable, the report confirmed that “a rising percentage of emerging infectious diseases has been fungal in nature, including multidrug-resistant species with considerable mortality such as Candida auris.”
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The conditions that would define a modern fungal plague are quietly assembling:

  • Drug resistance is outpacing the development of new antifungals, with only three major classes of drugs available — and resistance rising to all three.​
  • Climate change is expanding fungal habitats into previously safe regions​
  • Immunocompromised populations are growing due to aging, cancer treatment, transplantation, and HIV
  • Diagnostics are inadequate, with fungal infections routinely mistaken for bacterial pneumonia or influenza until too late
  • Funding gaps have left fungal research chronically underfunded compared to bacterial and viral threats

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German broadcaster DW reported in 2025 that “globally, fungal infections now account for three times the number of fatalities as malaria,” with up to 60% of C. auris infections proving fatal.

The Indoor Air Quality Connection

For homeowners, renters, and indoor air quality professionals, the implications of the fungal threat don’t stop at hospital ICUs.

Aspergillus fumigatus is one of the most common mold species found in water-damaged buildings. Any home or commercial space with moisture intrusion, leaking pipes, flood damage, or inadequate ventilation is a potential breeding ground.

Hospital-associated outbreaks have repeatedly been traced to construction dust, HVAC systems, and disturbed building materials.
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The same environmental conditions that allow Stachybotrys chartarum (black mold) to colonize a home — sustained moisture, poor ventilation, organic building materials — also allow Aspergillus species to establish themselves.

While black mold produces mycotoxins that cause respiratory and neurological symptoms, Aspergillus carries the additional risk of triggering life-threatening invasive infections in vulnerable occupants.

Research confirms that “hospitals already grapple with Aspergillus outbreaks after building renovations or severe dust storms,” while “intensive care units report stubborn cases in patients recovering from influenza or COVID-19.”

The COVID-19 pandemic itself created a surge in Aspergillus co-infections, particularly after the second wave, which saw an unprecedented rise in invasive fungal sinusitis cases.

Conclusion

The fungi spreading across our warming planet do not move with the drama of a virus making headlines.

They grow silently in soil, drift invisibly through hospital corridors, and colonize the lungs and bodies of the vulnerable with no early warning.

Aspergillus fumigatus and Candida auris represent the convergence of three crises at once: antimicrobial resistance, climate change, and chronic underinvestment in fungal science.

The WHO, CDC, and leading mycologists have all reached the same conclusion: we are not prepared.

The tools to diagnose, treat, and contain these organisms are inadequate for the scale of the threat taking shape.

As Dr. van Rhijn and colleagues at the University of Manchester have shown, fungal pathogens will likely impact most areas of the world in the future — including regions where they have never been seen before.
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The lesson for homeowners, renters, building managers, and healthcare workers is the same one that mold professionals have repeated for decades: moisture is the enemy.

Control water intrusion, maintain indoor air quality, and don’t ignore mold growth of any kind. What begins as a water stain or musty smell can, in the wrong circumstances, carry lethal consequences.

Across the world, millions of people may be slowly getting sicker from hidden fungal infections that are often missed or misdiagnosed.

Instead of being treated for the real cause, many receive medications that can weaken the body’s defenses or even help fungi grow stronger — creating the perfect storm for a modern-day plague.

As the World Health Organization (WHO) stated bluntly in 2022;

“Fungal pathogens are a major threat to public health and yet they are often overlooked. The Fungal Priority Pathogens List is a call to action for governments, researchers, and the pharmaceutical industry to prioritize fungal pathogens and act before the threat worsens.”

The real question is: are we paying attention before it’s too late?

References

Authors

  • Moe Bedard

    Moe is a certified mold inspector and remediator with 15+ years of experience, founder of Black Mold News, and CEO of Mold Safe Solutions—making him one of the most trusted names in the industry.

  • Chase Bedard is the Lead Science Researcher and Editor for Black Mold News and a graduate of the University of California, San Diego in cell biology. He is also a certified mold inspector and remediator with Mold Safe Solutions, combining scientific training with real-world field experience investigating mold and its health effects in homes and buildings.

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