Stop Neglecting Fungal Diseases

In 2023, 24 US citizens traveled to Mexico for cosmetic surgery and returned with life-threatening fungal meningitis caused by a rare mold, Fusarium solani. Most of these individuals were young, healthy mothers. Twelve of them died. Around the same time, more than 100 workers at a paper mill in Michigan developed blastomycosis, a severe disease that typically affects the lungs when people inhale the environmental fungus Blastomyces. Most were young or middle-aged men with no underlying health problems. These recent outbreaks dispel three common myths: that fungal diseases are rare, that they affect only people with weakened immune systems, and that they aren’t deadly to healthy people.

As Angel N. Desai and George R. Thompson III note in “Foiling the Growing Threat of Fungal Pathogens” (Issues, Winter 2025), hundreds of fungi can cause human disease. As they evolve, fungi are getting better at infecting healthy people, finding unique ways to spread, and developing resistance to available medications. The highly resistant fungal pathogen Candida auris was first identified in a handful of patients in 2016 in three states, and now tens of thousands of people are affected across 46 states. In the last year, antifungal drugs have stopped working for some cases of ringworm, one of the most common fungal skin diseases in the United States. Both topical antifungals and oral medicines fail to treat this skin infection, and this new species causing these resistant infections is spreading rapidly and causing severe health consequences. “Athlete’s foot” is now becoming untreatable “athlete’s leg.”

The number of deaths from fungal diseases in the United States has substantially increased over the last decade. The physical and mental health toll of these diseases and associated costs are substantial. Some patients suffer lifelong complications, contributing to America’s chronic disease epidemic. Better systems and tools to address fungal diseases are urgently needed.

For example, the nation needs improved monitoring of fungal diseases. Today, only two fungal infections out of hundreds—Candida auris and coccidioidomycosis (commonly called valley fever)—are nationally notifiable. Building national surveillance of fungal diseases would help identify populations at risk and potential exposures, information that can help increase awareness among health care providers and the public and identify prevention measures.

We need better and more accessible diagnostic tests. Fungal disease tests are not widely available for many infections and are often unreliable. Delays in testing can be a matter of life and death. Testing for some fungi is available only at specialized laboratories, and because of Clinical Laboratory Improvement Amendment restrictions and low reimbursement rates, office-based tests are rarely used in laboratories serving primary care clinics or long-term care facilities.

We need new antifungals with novel mechanisms of action. The current armamentarium of antifungals is limited to only three main classes. Certain fungi, like C. auris and Fusarium solani, show resistance to all three classes, leaving patients without viable treatment options. New antifungals such as olorofim and fosmanogepix have recently been developed but are still not approved. However, more options are needed as fungi continue to adapt and develop resistance. Optimizing use of existing antifungals and performing antifungal susceptibility testing to guide therapy are essential to preserve available antifungal drugs.

Underpinning all, we need to advance knowledge about fungal infection epidemiology, diagnosis, and treatment to prevent, control, and treat the diseases they cause. This will require expanding awareness and education among physicians, nurses, pharmacists, laboratorians, and the public. It is vital that updated knowledge and research are paired with appropriate communication to help us “think fungi” and save lives.

Dallas J. Smith

Kaitlin Benedict

Jeremy Gold

Meghan Lyman

Nancy A. Chow

Tom Chiller

Angel N. Desai and George R. Thompson III expertly associate the critical link between increased human fungal disease and human activities that profoundly alter Earth’s biology. This perspective is supported by recently observed outbreaks of fungal diseases associated with deforestation and new road construction. Advances in medicine have also dramatically escalated the number of people with increased susceptibility to fungi, including individuals receiving steroids, immunomodulators, chemotherapy, or other biologics that alter host immunity. Individuals with advanced HIV infection remain at great risk for mycoses, or fungal infections, especially Cryptococcus meningitis. We applaud Desai and Thompson for sounding the alarm over the growing danger of fungi. Their call for a One Health approach is especially important as fungi threaten all biological kingdoms. For example, Batrachochytrium dendrobatidis has caused the extinction or decline in over 200 amphibian species.

Candidozyma auris and Sporothrix brasiliensis are two recently emerged fungal species that are major human threats. C. auris was first isolated in 2009 in Japan and is globally present. This fungus is particularly dangerous as it is usually resistant to one or more of our standard antifungals, and it can survive well on human skin and environmental surfaces. These aspects increase the likelihood of severe disease and for the fungus spreading in health care facilities, and there have been numerous outbreaks globally. In 2022, the World Health Organization identified C. auris as the second-highest fungal threat (after Cryptococcus). Reasons for the surprising emergence of C. auris include global warming, exposure to antifungal compounds, and interactions with environmental predators. Amoebae, worms, and other predators ingest fungi as food. However, over millennia, certain fungi developed mechanisms to subvert these hosts and kill them. For example, C. auris, Cryptococcus, Blastomyces, and Histoplasma can survive within and kill Acanthamoeba amoebae.

S. brasiliensis, first identified in 1998 but only named in 2007, causes skin infections and, more importantly, disseminated disease in bone, lung, and brain, among other sites. There is an ongoing epidemic of S. brasiliensis in the Brazilian state of Rio de Janeiro that is directly associated with contact with infected animals, particularly cats.Most infections occur in poorer individuals. Unfortunately, S. brasiliensis in humans and cats has spread to other Brazilian states and countries. A major challenge in controlling the threat in emerging countries is the care of unowned cats, which freely transmit the disease. This issue not only reinforces the need for One Health-based approaches but also highlights that public health problems must integrate both scientific and social strategies.

As these powerful examples of frightening new and emerging fungal diseases illustrate, a shift in mindset is urgently needed to control the health and social problems caused by mycoses globally. Investing proactively in health rather than in treating disease is essential, and it is necessary to discuss social and scientific prevention measures alongside new treatments and diagnostic methods. As Desai and Thompson perfectly highlight, it is time to stop neglecting fungal diseases.

Joshua D. Nosanchuk

Marcio L. Rodrigues