Leishmaniasis diagnosis. Doctor placing a tissue sample into a growth medium bottle. The tissue is from a lesion on the boy's leg. It is suspected that he has leishmaniasis, though the lesions can sometimes be confused with leprosy. The sample will be cultured to confirm the diagnosis. This cutaneous (skin) form, is the most common form of the disease. The lesions generally heal, though scarring is possible. Treatment is by drugs or by cryotherapy. Leishmaniasis is caused by Leishmania sp. protozoan parasites. They are transmitted to humans through the bite of an infected sandfly. Photographed in Ethiopia.