Leishmaniasis is a parasitic disease transmitted by the bite of infected sand flies. It is found in nearly 88 countries, from rain forests in Central and South America to deserts in the Middle East and west Asia. Some cases of the disease have also appeared in Mexico and Texas.

Leishmaniasis takes several different forms, including the most common cutaneous leishmaniasis, which causes skin sores, and the more severe visceral leishmaniasis, which affects internal organs such as the spleen, liver, and bone marrow. The World Health Organization (WHO) estimates that there are 1.5 million new cases of cutaneous leishmaniasis and 500,000 new cases of visceral leishmaniasis in the world each year.