Kala-azar is caused due to infection by the parasite called Leishmania donovani. Leishmania donovaniis is transmitted by sandfly bites in parts of Asia (primarily India), Africa (primarily Sudan) and South America. The common symptoms are: loss of appetite, fever, fatigue, enlargement of the liver, spleen and nodes and suppression of the bone marrow.
The term "kala-azar" comes from India where it is the Hindi for black fever.
Sleeping sickness - It is a parasitic disease of people and animals, caused by protozoa of the species Trypanosoma brucei and is transmitted by the tsetse fly. This disease isendemic in some regions of sub-Saharan Africa.
It is is characterized by fever, headaches, joint pains, and itching. Invasion of the circulatory and lymphatic system by the parasites is associated with severe swelling of lymph nodes.
The tsetse fly is the host for the parasite, which is transmitted by biting. The bite is sufficiently painful for it to be noticed, but only a few of the flies carry the infection.
When the fly bites, the parasite is able to enter the bloodstream via the bite, from where it passes over into the lymph and the central nervous system.
The flagellate reproduces in the blood, and a fly that bites an infected human may therefore itself become infected, and over the course of four to six weeks this fly may infect further humans.