African sleeping sickness

(African trypanosomiasis)

African sleeping sickness or African typanosomiasis is found in West, Central, and East Africa, confined between 15 degrees North and 20 degrees South latitude.

The disease is caused by infection with a protozoal parasite transmitted by the bite of an infected tsetse fly. They pass it on by biting large, warm-blooded animals and are responsible for the lack of horses and cows in some areas. The tsetse fly is about twice the size of a housefly or about the size of a honeybee, and recognizable by the scissor-like way it folds its wings when at rest. Only a small proportion of tsetse flies carry the disease but it is best to try to avoid being bitten. The tsetse fly bites during the day.

Although the risk to international travelers is relatively low, persons traveling to game parks and sparsely inhabited areas should take precautions. Tsetse flies appear to be attracted to moving vehicles, dark, contrasting colors, perfume, and aftershave lotions. The flies are capable of biting through lighter weight clothing. Areas of heavy infestation tend to be sporadically distributed and are usually well known to local inhabitants. Avoidance of such areas is the best means of prevention. Travelers at risk should use "DEET" containing insect repellents liberally and wear clothing of wrist and ankle length that blends with the background environment and is constructed of heavy, e.g., canvas weight, fabric.

The incubation period of acute trypanosomiasis ranges from 6 to 28 days, and travelers frequently become ill during their trips or shortly after returning home. Swelling at the site of the bite, five or more days later, is the first sign of infection. This is followed within two to three weeks by rash, fever, headaches, lethargy, confusion, and severe illness. The illness is serious but responds well to medical attention.

Chronic trypanosomiasis may not cause symptoms until months to years following travel to an endemic area,

No vaccine is available.