Leishmaniasis, a disease spread by a parasite carried by sand flies, is generally considered a tropical disease. Now, thanks to climate change, new research finds it's endemic to the United States.

It's called visceral leishmaniasis. It's spread by sandflies and fatal if left untreated. Fortunately, a new drug regimen holds promise.

Scientists caution that as the planet warms, more Americans could be exposed to disfiguring varieties of the Leishmania parasite. Overtreatment can be a problem, too, experts warn.