(a) The disease is caused by protozoa 'Trypanosoma brucei'. The protozoa are transmitted by tse-tse fly. It is known as sleeping sickness because of disturbed sleeping cycle. Early symptoms of this disease include fever, headache, joints pain and itching.

(b) Kala azar disease is caused by a protozoan parasite called Leishmania donovani. Because of the protozoa the disease is also known as Leishmaniasis.