Trypanosomiasis
Trypanosomiasis, also sleeping sickness, endemic, and sometimes epidemic, chronic disease caused by a protozoan blood parasite, genus Trypanosoma. In cattle and other animals, which serve as the reservoir for the protozoa, the disease is called nagana. Two variations of the disease occur in central and western Africa, both of them transmitted in the salivary glands of infected tsetse flies. The most common is caused by T. brucei gambiense, whereas a more local version is caused by T. brucei rhodesiense. African sleeping sickness begins with a chancre at the site of the insect bite, an accelerated heartbeat, an enlargement of the spleen, and rash and fever. Over the next few months the nervous system is attacked, with accompanying mood changes, sleepiness, lack of appetite, eventual coma, and, frequently, death. Chagas' disease, which more frequently attacks children, also involves fever and damage to the spleen and nervous system, as well as to the liver and the heart muscles. It i