Sleeping sickness, also known as African trypanosomiasis, is a parasitic disease that is endemic to Africa, and consists of two predominant types, East African and West African trypanosomiasis. The disease is contracted and spread from the bite of a fly, which then makes its way into the circulatory system where blood disseminates it throughout the body. Ultimately, the disease invades the central nervous system. At this point in the disease process, behavioral changes occur, for example, fearfulness may be displayed as well as mood swings. This disease is fatal if it is not treated.
General Etiology
African trypanosomiasis is caused from a bite of an infected tsetse fly which is the vector or carrier of the parasite. In very rare situations, a pregnant woman who has been bitten can pass the infection to her baby. Infection can also be transmitted by blood transfusion or organ transplant, but again, very rarely. The disease does not frequently occur in the United States; that is, it has been diagnosed in American travelers who traveled in Africa.
East African
East African trypanosomiasis is caused specifically by the parasite Trypanosoma brucei rhodesienses which is spread by tsetse flies serving as vectors (carriers) of the disease and transmit it to humans. When one is bitten by a tsetse fly that carries the parasite, the result is a red and painful sore or chancre. East African trypanosomiasis occurs in Eastern and Southeastern Africa, and the Centers for Disease Control reports that over 95 percent of diagnosed cases originate from the following areas: Uganda, Tanzania, Malawi, and Zambia. Each year, 500 to 1,000 cases of East African trypanosomiasis are reported to the World Health Organization.
West African
The etiology of West African trypanosomiasis is the parasite, Trypanosoma brucei gambiense that also, is transmitted by a bite from a tsetse fly. Tsetse flies are found in rural areas among thickets and along streams where there is vegetation. The Centers for Disease Control states that approximately 12,000 new cases of West African trypanosomiasis are reported to the World Health Organization each year. However, it is believed that more cases exist which have not yet been identified.
