Leishmaniasis is due to infection by vector-borne protozoa from the genus Leishmania. These protozoa exist as obligate intracellular parasites in human and mammalian hosts and are transmitted from host to host by certain species of sandfly. Depending on the Leishmania species involved, the resultant disease picture may range from a localized cutaneous ulcer through extensive mucocutaneous destruction to severe systemic disease.