Sleeping Sickness, African

(also African trypanosomiasis), in man, a disease caused by two species of parasitic protozoans of the genus Trypanosoma. African sleeping sickness occurs in many areas of Central, West, and East Africa. The sources of the causative agent are man and animals, including antelopes, swine, and goats.

African sleeping sickness is a transmissible disease endemic to some areas. It is transmitted by the tsetse fly, which becomes infected and passes the infection while sucking blood. Infection may also occur through the transfusion of infected blood and from medical instruments. The incubation period is two to three weeks. A lesion surrounded by a whitish area appears at the site of the bite. Attacks of fever continue for weeks, broken up by intermissions lasting several days. The body temperature rises to 40°-41°C, a skin rash appears, the lymph nodes and spleen become enlarged and weakness and insomnia develop. The second stage of the disease, which may last many months or years, is characterized by the dominance of the symptoms of central nervous system involvement. Insomnia is replaced by increasing drowsiness, especially in the morning and during the day. If not treated, diseased individuals often die.

Techniques used in the diagnosis of African sleeping sickness include the microscopic study of blood smears and cerebrospinal fluid. The disease is treated with chemotherapeutic agents. Preventive measures include the detection and treatment of diseased individuals and parasite carriers, the control of flies through the use of mosquito netting and repellents, and the use of chemotherapeutic agents.