Multiple choice Kala-azar is caused by : Trypanosoma cruzi Leishmania Trypanosoma brucei Trypanosoma gambiense Hydra vulgaris Reveal answer Fill a bubble to check yourself B Correct answer Explanation Visceral leishmaniasis (VL), also known as kala-azar, black fever, and Dumdum fever, is the most severe form of leishmaniasis. Leishmaniasis is a disease caused by protozoan parasites of the Leishmania genus.