Leishmania donovani is transmitted by sandfly bites in parts of Asia (primarily India), Africa (primarily Sudan) and South America (primarily Brazil) where all together there are an estimated half million cases per year. There are also several hundred cases yearly in Europe (primarily in the Mediterranean region) and a few in North America.
The infection can cause no or few symptoms but typically it is associated with fever, loss of appetite (anorexia), fatigue, enlargement of the liver, spleen and nodes and suppression of the bone marrow. The disease also increases the risk of other secondary infections. The first oral drug found to be effective for treating it is miltefosine.
The term "kala-azar" comes from India where it is the Hindi for black fever. The disease is also known as Indian leishmaniasis, visceral leishmaniasis, leishmania infection, black sickness, and black fever. The name "Leishmania donovani" honors two men: the British pathologist William Boog Leishman who in 1903 wrote about the protozoa that causes kala-azar and the researcher C. Donovan, who made the same discovery independently the same year.