TL;DR
Get health and wellness essentials delivered free — and shop member deals
- Fast, free delivery on millions of items
- Access to Prime Big Deal Days deals on October 6–7
- Prime Video, Amazon Music and more included
The CDC reports a fourfold increase in detected cases of Cladophialophora bantiana, a rare fungal infection that causes brain abscesses. The rise, observed between 2023 and 2025, has alarmed researchers because it affects people with healthy immune systems. The infection carries a mortality rate of up to 70%, and the exact cause of the surge remains under investigation.
The findings come from a study led by researchers at the University of Washington School of Medicine, published in the Morbidity and Mortality Weekly Report. The team analyzed samples processed by a national clinical reference laboratory between January 2009 and July 2026. During this period, they identified 48 confirmed cases and one probable case of C. bantiana infection. While the annual case count remained low, ranging from one to five cases per year from 2009 to 2023, it jumped to eight cases in 2024 and 14 cases in 2025.
The geographic distribution of these cases is widespread. Infections were detected in samples from 21 states and the District of Columbia. California reported the highest number of cases with six, followed by Florida and Texas with five each, and Pennsylvania with four. The median age of patients was 68 years. Most cases, 88%, were detected in intracranial central nervous system (CNS) tissue specimens, while 12% were found in lung specimens. This distribution supports the theory that the fungus enters the body through inhalation or direct inoculation via skin injuries before spreading to the brain.
The rate of detection has also changed significantly. The case rate more than tripled from an annual average of 8.4 cases per 1,000 CNS specimens in the 2017-2023 period to 26 cases per 1,000 specimens in 2025. This metric suggests that not only are more cases being found, but the proportion of brain abscesses caused by this specific fungus is rising relative to other causes.
High Mortality in Healthy Patients
The primary concern raised by this report is the vulnerability of immunocompetent individuals. Historically, severe fungal infections were largely associated with patients who had profound immunosuppression, such as those undergoing chemotherapy or organ transplants. However, Joshua Lieberman, MD, PhD, of the University of Washington, stated that it is “alarming” to see these infections in people with apparently healthy immune systems. The high mortality rate, reaching up to 70%, makes early diagnosis critical. Because the symptoms of a brain abscess can mimic other conditions, clinicians may not immediately suspect a fungal cause, potentially delaying life-saving treatment. The shift in patient demographics means that doctors must consider rare fungal pathogens even in patients without obvious risk factors.
As an affiliate, we earn on qualifying purchases.
Climate Change and Environmental Factors
Researchers are investigating why the incidence of C. bantiana is rising. While some of the increase may be due to better molecular testing and more specimens being submitted to labs, other factors are likely at play. Lieberman noted that climate change and a warming environment are prominent hypotheses. Evidence suggests that certain fungal pathogens are adapting to higher temperatures, which may enhance their ability to infect humans. Additionally, increased human encroachment into environmental reservoirs where the fungus lives could boost exposure risk. The exact source of the fungus and why it specifically targets the brain remain “a little bit of a mystery”, according to Lieberman. The true incidence is likely underestimated because growing molds in laboratory settings is difficult, leading to potential undersampling.
“It’s alarming that it occurs outside of those typical high-risk populations who have pretty profound immunosuppression.”
— Joshua Lieberman, MD, PhD, University of Washington School of Medicine
As an affiliate, we earn on qualifying purchases.
Unknown Causes and True Prevalence
Despite the clear data on rising cases, several key questions remain unanswered. The exact cause of the fourfold increase is not confirmed. While climate change and improved detection are leading theories, researchers cannot yet quantify the impact of each factor. Furthermore, the true incidence of C. bantiana infections is unknown. Because the fungus is difficult to culture and identify, many cases may go undiagnosed. It is also unclear whether the geographic distribution will continue to be evenly spread or if certain regions will see higher concentrations as environmental conditions change. The biological mechanism that allows this specific fungus to cross the blood-brain barrier so effectively also remains poorly understood.
medical fungal infection microscope
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
Clinical Guidance and Surveillance
Health officials and researchers are urging clinicians to maintain a high index of suspicion for rare fungal infections in patients with brain abscesses, especially when routine tests fail to provide a diagnosis. Treatment protocols typically involve surgical excision of the abscess combined with antifungal therapy using drugs like liposomal amphotericin B, posaconazole, voriconazole, or flucytosine. Continued surveillance by specialized laboratories is necessary to track whether the upward trend continues. Future research will likely focus on understanding the environmental reservoirs of the fungus and developing faster diagnostic tools to identify C. bantiana earlier in the course of the disease.
neuroimaging MRI for brain abscess
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
Key Questions
What is Cladophialophora bantiana?
Cladophialophora bantiana is a rare mold found in the environment, particularly in soil and decaying plant matter. It is known for causing serious infections in the central nervous system, most commonly presenting as brain abscesses.
Who is at risk for this infection?
While fungal infections often affect immunocompromised people, C. bantiana is notable for infecting people with healthy immune systems. The recent CDC report highlights that it poses a significant threat to the general population, with a median patient age of 68.
How is the infection treated?
Treatment usually requires a combination of surgical removal of the brain abscess and prolonged antifungal medication. Common drugs used include amphotericin B, posaconazole, voriconazole, and flucytosine. Early diagnosis is critical for survival.
Is the increase in cases due to climate change?
Researchers suggest that climate change and warming temperatures may be contributing factors, as some fungi adapt to higher heat. However, improved testing methods and increased specimen submissions also play a role. The exact cause of the rise is still under investigation.
Source: rss
Halloween Picks
halloween
As an affiliate, we earn on qualifying purchases.
