Infectious disease caused by Leishma-nia donovani, spiral-shaped protozoan parasites which occur in the tropics and subtropics. In Western Europe leishmaniasis is an introduced disease. The parasite develops in the cells of blood-vessel walls and in tissue cells. A small blood-sucking mosquito transmits the parasite from infected people to healthy ones. There are various forms of leishmaniasis. Kala-azar occurs in the Mediterranean region and in India. The parasite poor wood supply attacks the liver and the spleen, resulting in fever and anaemia, and sometimes a dark colouring in the skin of the face. It also occurs in cutaneous form (Eastern sore), with characteristic swelling of the skin and ulcers. This condition occurs in the Mediterranean, the Middle East, Africa and parts of South America. The cutaneous form is characterized by one or several large