Full Breakdown
Rise of Brain-Infecting Fungus Cladophialophora bantiana Across the United States
By Drooid · · How we work
Core Event
A rare black yeast-like mold, *Cladophialophora bantiana*, is increasingly identified as the cause of brain infections in the United States. The Centers for Disease Control and Prevention (CDC) reported that detections of the fungus nearly quadrupled between 2023 and 2025, with annual confirmed cases climbing from eight in 2024 to 14 in 2025. The pathogen can invade the brain after inhalation or entry through a skin wound, traveling via the bloodstream.
Background & Context
Historically, *C. bantiana* infections were exceptionally uncommon, with the University of Washington microbiology laboratory recording only one to five cases per year from 2009 through 2023. The fungus differs from many opportunistic fungi because roughly half of the infections occur in otherwise healthy individuals. Between early 2009 and mid-2026, researchers identified 48 confirmed cases and one probable case across 21 states and the District of Columbia, with a median patient age of 68 years.
Data & Statistics
- Geographic distribution: The highest state counts were California (six cases), Florida (five), Texas (five), and Pennsylvania (four).
- Specimen positivity: 88 % of detections were in brain tissue samples; 12 % were in lung tissue.
- Detection rate: Positive findings rose from 8.4 cases per 1,000 brain-tissue specimens (2017–2023) to 26 per 1,000 specimens in 2025.
- Fatality: A systematic review in *Medical Mycology* estimates a 60 %–70 % mortality rate despite aggressive treatment.
Official Statements & Responses
The CDC report emphasized that the reasons for the apparent increase are unknown and called for a systematic national reporting mechanism to improve tracking. Public-health experts advise clinicians to consider *C. bantiana* when evaluating patients with brain abscesses, noting that early diagnosis is difficult because the infection often lacks external signs. Recommended management includes surgical removal of infected tissue combined with multiple antifungal medications.
Why It Matters
The rising incidence and high fatality rate pose a growing public-health challenge, especially given the pathogen’s ability to affect healthy adults and the difficulty of detection—standard spinal-fluid PCR tests can return negative results even in fatal cases. Enhanced surveillance and clinician awareness are essential to mitigate morbidity and mortality as the fungus spreads across a broad geographic area.