African Trypanosomiasis FAQs

What is African trypanosomiasis?

There are two types of African trypanosomiasis (also called sleeping sickness); each is named for the region of Africa in which they were found historically. East African trypanosomiasis is caused by the parasite Trypanosoma brucei rhodesiense. West African trypanosomiasis is caused by the parasite Trypanosoma brucei gambiense. Both types of African trypanosomiasis are transmitted by the tsetse fly which is found only in rural Africa.

How is African trypanosomiasis spread?

A person will get East or West African trypanosomiasis if he or she is bitten by a tsetse fly infected with the Trypanosoma brucei rhodesiense or Trypanosoma brucei gambiense parasite respectively. The proportion of tsetse flies that are infected with these parasites is low. The tsetse fly is found only in rural Africa. Occasionally an infected pregnant woman may pass T. brucei gambiense infection to her baby. Other routes of transmission are possible though rare and poorly documented (sexual, blood transfusion and organ transplantation).

Is African trypanosomiasis a serious illness?

Yes. East and West African trypanosomiasis are eventually fatal if not treated.

Where can you become infected with African trypanosomiasis?

East African trypanosomiasis is found in rural parts of Eastern and Southeastern Africa. In 2020, fewer than 100 cases of East African trypanosomiasis were reported to WHO ( icon).

West African trypanosomiasis is found in rural parts of central Africa and in a few areas of West Africa. In 2020, fewer than 600 cases of West African trypanosomiasis were reported to WHO; more than 50% of these were reported by the Democratic Republic of Congo ( icon).

What are the signs and symptoms of African trypanosomiasis?

Infection occurs in two stages: a first stage where the parasites are found in the blood and lymphatic system, followed by a second stage after the parasites invade the central nervous system. East African trypanosomiasis is a more acute disease than West African trypanosomiasis, progressing to the second phase within a few weeks. West African trypanosomiasis disease progresses more slowly, with a mean duration estimated at 3 years. With East African trypanosomiasis, a bite by the tsetse fly is often painful and can develop into a red sore, also called a chancre. This reaction is rarely seen with West African trypanosomiasis. Fever, severe headaches, irritability, extreme fatigue, swollen lymph nodes, and aching muscles and joints are common symptoms of sleeping sickness. Some people develop a skin rash. Progressive confusion, personality changes, and other neurologic problems occur after infection has invaded the central nervous system (second stage). If left untreated, the illness becomes worse and death will occur within months.

How soon after infection will I have symptoms of African trypanosomiasis?

For East African trypanosomiasis, symptoms usually occur within 1 to 3 weeks after an infective bite. For West African trypanosomiasis, symptoms may be minimal or intermittent during the first months of infection. They are usually apparent within a few months to a year after getting an infected tsetse fly bite.

What should I do if I think I may have African trypanosomiasis?

If you suspect that you may have African trypanosomiasis, immediately consult with your health care provider. There are several tests that can be done to look for the parasite (e.g., skin biopsy of the chancre, blood tests, and a spinal tap).

What is the treatment for African trypanosomiasis?

Medical treatment of African trypanosomiasis should begin as soon as possible and is guided by the infected person’s laboratory results. Hospitalization for treatment is usually necessary. Follow-up may require lumbar puncture every 6 months (or sooner if symptoms return) for 2 years.

Once infected, am I immune to African trypanosomiasis?

Even if you had the disease once, you can become re-infected.

Who is at risk for contracting African trypanosomiasis?

The tsetse flies that transmit African trypanosomiasis are found in rural areas in endemic countries. They inhabit forests and savannah areas as well as areas of thick vegetation along rivers and waterholes, depending on the species of fly. Travelers to urban areas in those endemic countries are at minimal risk, although transmission has been observed in some urban settings in the past. The flies bite during daylight hours. In areas where the disease is present, most flies are not infected with the parasite that causes African trypanosomiasis, so the risk of infection increases with the number of times a person is bitten by the tsetse fly. The persons most likely to be exposed to the parasite that causes African trypanosomiasis infection are hunters and villagers with infected cattle herds. Tourists and others working in or visiting game parks may be at risk for contracting African trypanosomiasis if they spend long periods of time in rural areas where the disease is present. Since the tsetse flies that transmit African trypanosomiasis are only found in endemic countries within Africa, the disease cannot be contracted within the United States.

Can I take a medication to prevent African trypanosomiasis?

There is neither a vaccine nor recommended drug available to prevent African trypanosomiasis.

How can I prevent African trypanosomiasis and prevent other insect bites?

  1. Wear protective clothing, including long-sleeved shirts and pants. The tsetse fly can bite through thin fabrics, so clothing should be made of medium-weight material.
  2. Wear neutral-colored clothing. The tsetse fly is attracted to bright colors and very dark colors.
  3. Inspect vehicles for tsetse flies before entering. The flies are attracted to moving vehicles.
  4. Avoid bushes. The tsetse fly is less active during the hottest period of the day. It rests in bushes but will bite if disturbed.
  5. Use insect repellant. Though insect repellants have not proven effective in preventing tsetse fly bites, they are effective in preventing other insects from biting and causing illness.


Page last reviewed: February 25, 2022