African Trypanosomiasis (sleeping sickness)

African trypanosomiasis is a parasitic infection transmitted by the bite of the tsetse fly. The tsetse fly lives only in rural areas in Africa, between the 15th parallel north and the 20th parallel south, chiefly in dense vegetation along rivers, lakes, and streams and in the woodlands and thickets of the savannah.  The parasite is inoculated into a human or animal as the tsetse fly takes a blood meal. Early symptoms may include fever, weakness, headache, joint pains, rash, itching, edema, and enlargement of lymph nodes. In the late stages of the disease, when the parasite has invaded the nervous system, the sufferer becomes apathetic, has difficulty concentrating, and experiences sudden mood swings. In the final stages, the victim becomes so lethargic that even simple activities such as eating and speaking require extraordinary effort. The person ultimately becomes comatose and dies. There are two types of African trypanosomiasis, caused by different parasites: Trypanosoma brucei gambiense, which causes a chronic infection that progresses slowly over years and which is found chiefly in western and central Africa, and Trypanosoma brucei rhodesiense, which progresses rapidly over several weeks and which occurs primarily in eastern and southern Africa.

Treatment depends upon the stage of disease. Many of the drugs used to treat African trypanosomiasis have significant toxicities. The best means of prevention is to avoid areas infested with tsetse flies, which are usually known to local inhabitants. Insect repellents are ineffective. Tsetse flies are attracted to moving vehicles and dark, contrasting colors, and can bite through lightweight clothing. Travelers at risk should therefore wear long sleeves and long pants of medium weight fabric in neutral colors that blend with the environment.