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African Trypanosomiasis

• African trypanosomiasis [tri-PAN-o-SO-my a-sis], also called sleeping sickness, is a serious parasitic disease that is always fatal without treatment.
• The disease is spread by the bite of tsetse flies, found only in Africa. It occurs in two forms: East African trypanosomiasis and West African trypanosomiasis.
• There is no vaccine or drug to prevent African trypanosomiasis. Travelers to areas where the disease occurs should take precautions to avoid tsetse fly bites.

What is African trypanosomiasis?

African trypanosomiasis, also called sleeping sickness, is a serious tropical disease that is always fatal without treatment. There are two types of African trypanosomiasis, named for the regions in Africa in which they are found: East African trypanosomiasis and West African trypanosomiasis.

What is the infectious agent that causes African trypanosomiasis?

East African trypanosomiasis is caused by the parasite Trypanosoma brucei rhodesiense. West African trypanosomiasis is caused by Trypanosoma brucei gambiense. The parasites are spread by tsetse flies, found only in Africa.

Where is trypanosomiasis found?

East African trypanosomiasis occurs in parts of Eastern and Central Africa, including Uganda, Kenya, Tanzania, Malawi, Ethiopia, Zaire, Zimbabwe, and Botswana. West African trypanosomiasis is found in parts of Western and Central Africa.

How do people get trypanosomiasis?

People get African trypanosomiasis from the bite of an infected tsetse fly. In rare cases, an infected pregnant woman can pass the infection to her baby. Infection can also be transmitted by blood transfusion or organ transplant, but very rarely.

What are the signs and symptoms of trypanosomiasis?

A tsetse fly bite is often painful and can develop into a red sore, called a chancre [SHAN-ker]. In cases of East African trypanosomiasis, other symptoms occur within 1 to 4 weeks of infection and include fever, severe headache, irritability, extreme tiredness, swollen lymph glands, and aching muscles and joints. Weight loss and a body rash are also common. Infection of the central nervous system causes confusion, personality changes, slurred speech, seizures, and difficulty in walking and talking. If left untreated, the illness becomes worse, and death occurs within several weeks to months.

Persons with West African trypanosomiasis sometimes develop a chancre 1 to 2 weeks after the tsetse fly bite. Other symptoms occur several weeks to months later and include fever, rash, swelling around the eyes and hands, severe headaches, extreme tiredness, and aching muscles and joints. Some people develop swollen lymph glands on the back of the neck. Weight loss occurs as the illness worsens. Infection of the central nervous system causes personality changes, irritability, loss of concentration, confusion, slurred speech, seizures, and difficulty in walking and talking. Many patients sleep for a long time during the day and have trouble sleeping at night. Without treatment, the illness gets worse and results in death several months to years after infection.

How is trypanosomiasis diagnosed?

Trypanosomiasis can be diagnosed by laboratory tests on blood and spinal fluid.

Who is at risk for trypanosomiasis?

East African trypanosomiasis is usually confined to woodland and savannah areas away from places where people live. Tourists, hunters, game wardens, fishermen, and other persons who work in or visit game parks in East and Central Africa are at greatest risk for illness.

The tsetse flies that spread West African trypanosomiasis can be found in Western and Central African forests and in areas of thick shrubbery and trees by rivers and waterholes. The risk of infection increases with the number of times a person is bitten by a tsetse fly. Therefore, tourists are not at great risk for getting West African trypanosomiasis unless they travel and spend long periods of time in rural areas of West and Central Africa.

What is the treatment for trypanosomiasis?

Medicine for the treatment of African trypanosomiasis is available. Treatment should be started as soon as possible and is based on the infected person's symptoms and laboratory tests results. Patients need to be hospitalized for treatment and require periodic follow-up exams for 2 years.

How common is trypanosomiasis?

Worldwide, 20,000 new cases of both East and West African trypanosomiasis are reported each year. Since 1968, 17 cases of East African trypanosomiasis have been reported in the United States; few cases of the West African form of the disease have been reported.

How can trypanosomiasis be prevented?

There is no vaccine or drug to prevent African trypanosomiasis. When traveling in areas where the disease occurs, take these precautions against bites from tsetse flies and other insects:

• Wear protective clothing, including long-sleeved shirts and pants. Tsetse flies can bite through thin fabrics, so clothing should be made of thick material.
• Wear khaki or olive-colored clothing. Tsetse flies are attracted to bright and dark colors.
• Use bednets.
• Inspect vehicles for tsetse flies before entering.
• Do not ride in the back of jeeps, pickup trucks, or other open vehicles. Tsetse flies are attracted to dust churned up by moving vehicles and animals.
• Avoid bushes. Tsetse flies are less active during the hottest part of the day; they rest in bushes and will bite if disturbed.
• Use insect repellent. Although repellents have not proven effective in preventing tsetse fly bites, they are effective in preventing other insects from biting and causing illness.

This fact sheet is for information only and is not meant to be used for self-diagnosis or as a substitute for consultation with a health-care provider. If you have questions about the disease described above, consult a health-care provider.

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