Fourfold Increase in Cladophialophora bantiana Infections in the US (2023-2025)

A recent study conducted by researchers from the University of Washington and the Centers for Disease Control and Prevention has revealed a dramatic increase in infections caused by the fungus Cladophialophora bantiana in the United States. From 2023 to 2025, the number of detected cases rose fourfold, raising alarms about the public health implications of this rare but deadly pathogen. The findings were published in the Morbidity and Mortality Weekly Report, based on data collected from January 2009 to July 2026.

Cladophialophora bantiana is a highly virulent mold known for its severe impact on the central nervous system, with a staggering case-fatality rate between 60% and 70%. Alarmingly, half of the infected individuals do not have compromised immune systems, complicating the understanding of the infection's transmission and risk factors. The primary suspected routes of infection include inhalation or infection through skin lesions, leading to brain abscesses. However, the epidemiology of this fungus remains poorly understood, as it has rarely been isolated from environmental sources.

The study analyzed 49 confirmed cases of C. bantiana, with the median age of patients being 68 years. Notably, 88% of these infections were found in brain tissue, while 12% were detected in lung samples, supporting the theory that inhalation may be a significant route of infection. The data indicated a gradual increase in cases from 2009 to 2023, with a sharp rise to 14 cases in 2025, marking a 210% increase in detection rates per 1,000 CNS samples compared to previous years.

Cases were reported across 21 states, with the highest numbers originating from California, Florida, Texas, and Pennsylvania. The researchers emphasized the need for heightened awareness among clinicians regarding the rising incidence of C. bantiana, especially in patients exhibiting symptoms of brain abscesses. They recommend that testing for this fungus be conducted through clinical reference laboratories that specialize in molecular testing for fungal infections.

As the incidence of Cladophialophora bantiana continues to rise, the authors advocate for surgical excision when feasible, alongside combination antifungal therapy. Although the optimal antifungal regimen remains uncertain, the study suggests that a triple therapy approach may offer some effectiveness. Clinicians are urged to remain vigilant and proactive in diagnosing and treating this dangerous fungal infection as its prevalence escalates.