A rare fungal pathogen that can cause severe, treatment-resistant infection of the cornea and potentially destroy vision was identified as the cause of a healthcare-associated outbreak at an ophthalmology clinic in New York City in 2024, according to an investigation published in the CDC's Morbidity and Mortality Weekly Report in 2026. The outbreak, involving Purpureocillium lilacinum — a filamentous mold found naturally in soil and water that has no approved antifungal standard treatment protocol — affected multiple patients who underwent procedures at the same ophthalmology clinic and developed keratitis (corneal infection) as a healthcare-associated complication.
A companion MMWR investigation published simultaneously documented a pseudo-outbreak of Purpureocillium lilacinum skin infections at a dermatology clinic in Washington state, where investigation determined that the infections were not true healthcare-associated transmissions but rather consecutive community-acquired infections that had been identified through enhanced surveillance. The clinical distinction between the two investigations — a true outbreak at the ophthalmology clinic versus a pseudo-outbreak at the dermatology clinic — highlights both the complexity of healthcare-associated infection surveillance and the growing clinical importance of Purpureocillium lilacinum as a pathogen in clinical settings.
