Leishmania parasites are named after W. B. Leishman, who first associated the organisms with the initial symptoms of the disease. The disease, termed leishmaniasis or leishmaniosis, is an example of a zoonosis that reaches man through an insect. The causative agents are different species of the parasite, which are transmitted by sandfly of the Phlebotomus (Old World) and Lutzomyia (New World) genera. Leishmaniasis is not a single entity but comprises an assortrnent of syndromes with characteristic clinical, histopathological and immunological features. The World Health Organization (WHO) has estimated that about three million human beings suffer the diseases, 12 million are infected, and 350 million live in risk areas