Leishmania Donovani

Leishmania donovani is a single-celled parasite that causes visceral leishmaniasis, also known as kala-azar, the most severe form of leishmaniasis, attacking the immune system's mononuclear phagocyte cells and damaging the spleen, liver and bone marrow. It is spread by the bite of infected sandflies and is present across tropical and temperate regions including parts of Africa, especially Sudan, as well as China, India, Nepal, southern Europe, Russia and South America, with roughly 350 million people considered at risk worldwide and about half a million new cases estimated each year. The parasite exists in two distinct forms: a rounded, non-motile form inside human cells and an elongated, flagellated form inside the sandfly. It was independently identified in 1903 by British medical officers William Leishman and Charles Donovan.