Americans, it turns out, can be exposed to Leishmania parasites without leaving the country. The parasites are currently endemic in Texas and Oklahoma, and new studies suggest that they might be present in other states, including Florida. While reported cases of leishmaniasis contracted in the U.S. are currently negligible, they may soon be on the rise: As climate change pushes rodent and sand-fly habitats northward, scientists caution that in the future, an increasing number of U.S. residents could be exposed to different varieties of the flesh-eating parasite. Some strains of Leishmania parasites can be life-threatening. The one currently present in the U.S., Leishmania mexicana, induces milder symptoms and, over time, can heal on its own. But if doctors fail to recognize it, or overreact to it, damages caused by wrong therapies and unnecessary toxic systemic medication can be worse than the disease itself. Bridget McIlwee, an Illinois-based dermatologist, has treated patients who contracted leishmaniasis in Texas. She wants her colleagues to be more aware of the parasite’s expansion into the U.S. “It’s a pretty striking difference for a disease that we used to think of as limited to South America now extending as far north as Canada,” she says, “potentially within the next several decades.”