S. brasiliensis is causing widespread infections in Brazil and expanding into neighboring countries. Cases have not been detected in the United States to date. However, the experience in Brazil shows that once established in a population, these infections may spread widely. Given the travel and exposure patterns of humans and cats, US physicians and veterinarians need to be prepared to recognize and treat infections caused by S. brasiliensis. Sporothrix brasiliensis is a fungus that is increasingly causing disease in cats and people in Brazil and parts of South America. Sporothrix brasiliensis has been spreading over time. Before 1990, Sporothrix brasiliensis was only known to be in Southeastern Brazil, near Sao Paolo and Rio de Janeiro. By 2018, cases of sporotrichosis—a fungal infection caused by S. brasiliensis—had been identified in eight more states across southern and eastern Brazil. Between 1998–2016, over 4,500 human cases spread by cats were identified. S. brasiliensis was also recently found in Argentina and Paraguay, and there is concern that it could spread to other countries through the movement of sick animals. S. brasiliensis can spread directly from an infected animal to a person or to other animals and make them sick with sporotrichosis. People can get sporotrichosis caused by S. brasiliensis from the bite or scratch of an infected cat. Other species of Sporothrix rarely spread through animal contact. When people get S. brasiliensis infections from cats, the symptoms are similar to or more severe than those of sporotrichosis caused by other species of Sporothrix.