Overview

• More than half of the 25 devices tested were abundantly colonized with fungi and about 80% of identified species are capable of causing illness
• The dominant species, Cystobasidium minutum, was absent from users’ oral microbiota and produced chronic bronchitis features in mice
• Researchers did not examine vape liquids for contamination and suggest fungi may originate from air, hands, existing liquid contaminants or device residues
• Experts caution that the small sample size and early‐stage design limit conclusions about population-level health risks
• Investigators urge routine cleaning of mouthpieces and call for larger epidemiological and microbiological studies to quantify potential dangers