Cases of a certain, deadly fungal infection that attacks the brain are still rare but reports have increased fourfold in recent years, according to the U.S. Centers for Disease Control and Prevention.
The fungus that causes the infections is called Cladophialophora bantiana. It is described as a “neurotropic fungus,” meaning that it targets the central nervous system (CNS), and its fatality rate is 60% to 70%, with 48 confirmed cases reported from January 2008 through this July. That “fourfold” increase in cases occurred from 2023 to 2025.
Per the New York Post, this fungus basically “liquifies” the brain. Medical literature describes it as a cause of brain abscesses and sometimes further fungal infection.
A description of the fungus from Adelaide University in Australia said it has colonies that are “moderately fast growing, olivaceous-grey, suede-like to floccose,” with conidia spores “formed in long, sparsely branched, flexuose, acropetal chains from undifferentiated conidiophores.” According to the CDC, it is a “a highly virulent, neurotropic dematiaceous [dark due to melanin in cell walls] mold.”
“National surveillance does not exist, and neither the environmental reservoir nor the route of infection is fully understood,” said the CDC in its Oct. 15 Morbidly and Mortality Weekly Report.
Cases of Cladophialophora bantiana have originated in 22 jurisdictions in 21 states. Most (six) have been reported in California, though five have been reported in Florida and four in Pennsylvania.
“Experts think the route of infection is inhalation or infection of a skin lesion, followed by spread to the brain, where it causes an abscess,” said the Center for Infectious Disease Research & Policy Research and Innovation Office at the University of Minnesota, writing about the fungus earlier this month. “But little is known about the risk factors or epidemiology of the fungus.”
According to the Cleveland Clinic, brain abscesses are collections of “pus and other materials in your brain,” and are a medical emergency. A 2017 study published in The Surgery Journal noted that intrafungal cerebral abscesses are known as “the great mimickers” because they can be mistaken for other conditions like cancer or lymphoma.
That study mentioned two cases linked to C. bantiana. In one, a 44-year-old man who presented with headaches and vision loss died despite eventual antifungal treatment and surgery, while a 54-year-old man recovered after antifungal treatment and surgery.
Canada’s government has noted that C. bantiana is found worldwide. Authors of the CDC research also said a 2024 study of 23 patients in France that found surgical excision or drainage of brain abscesses was associated with more favorable outcomes.
“When possible, surgical excision should be considered, concurrently with administration of combination antifungal therapy,” the CDC report said.
Authors of the CDC report also stressed that “further research into epidemiologic risk factors and potentially evolving virulence are warranted,” since the cause for the increase in C. bantiana cases is unknown. They also urged systematic reporting of cases and consideration of C. bantiana when patients present with brain abscesses.
“Despite its virulence, relatively little is known about the risk factors for or epidemiology of this fungus,” said the report. In around half of patients, there is no preceding immunocompromising condition and many patients don’t have similar exposure histories or risk factors.
