African Trypanosomiasis (African Sleeping Sickness)

Description

Trypanosomiasis is a systemic disease caused by the parasite Trypanosoma brucei. East African trypanosomiasis is caused by T. b. rhodesiense, and West African trypanosomiasis by T. b. gambiense. It is transmitted by the bite of the tsetse fly, a gray-brown insect about the size of a honeybee.

Occurrence

African trypanosomiasis is confined to tropical Africa between 15° north latitude and 20° south latitude, or from north of South Africa to south of Algeria, Libya, and Egypt. According to WHO 45,000 cases of trypanosomiasis were reported in 1999, however the actual prevalence of cases is estimated to be between 300,000 to 500,000.

Risk for Travelers

Tsetse flies inhabit rural areas only, living in the woodland and thickets of the savannah and the dense vegetation along streams. Although infection of international travelers was considered rare, the number of cases in travelers, primarily to East African game parks, has increased in recent years. Approximately 1 case per year has been reported among U.S. travelers. Travelers visiting game parks and remote areas should be advised to take precautions. Travelers to urban areas are not at risk.

Clinical Presentation

Signs and symptoms are initially nonspecific (fever, skin lesions, rash, edema, or lymphadenopathy); however, the infection progresses to meningoencephalitis. Symptoms generally appear within 1 to 3 weeks of infection. East African trypanosomiasis is more acute clinically, with earlier central nervous system involvement than in the West African form of the disease. Untreated cases are eventually fatal.

Prevention