Microbiologists warned that Sporothrix brasiliensis, a dimorphic fungus first identified in Brazil in the 1990s, has killed thousands of cats and infected over 11,000 people across South America. CDC senior adviser Shawn Lockhart highlighted the ongoing surge during the ASM Microbe conference, noting recent cases in Paraguay, Chile, Argentina and Uruguay. He cautioned that the pathogen could soon appear in the United States and strain clinics.

The fungus spreads uniquely through its yeast phase, which cats can transmit by scratches, bites, grooming or sneezing. Infected felines develop oozing ulcers that, without antifungal therapy, become fatal. Laboratory tests show yeast survives up to ten weeks on stainless steel, far longer than common pathogens, making thorough disinfection with bleach or ethanol essential even after standard cleaning.

Lockhart urged U.S. veterinarians to flag any sporotrichosis cases to local public‑health labs, noting that imported cats only need a health certificate, which can miss latent infection. Because the organism persists on surfaces, missed spots in clinics could spark wider transmission. Quickly, immediate reporting and rigorous cleaning and continual monitoring remain the only practical defenses against a U.S. incursion.