Visceral leishmaniasis: A chronic and potentially fatal parasitic disease of the viscera (particularly the liver, spleen, bone marrow and lymph nodes) due to infection by Leishmania donovani. Also known as Kala-azar.
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.
Visceral leishmaniasis can cause no or few symptoms but typically is associated with fever, loss of appetite (anorexia), fatigue, enlargement of the liver, spleen and nodes and suppression of the bone marrow. Visceral leishmaniasis also increases the risk of other secondary infections. The first oral drug found to be effective for treating visceral leishmaniasis is miltefosine.
The name "Leischmania 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.