West African trypanosomiasis is a disease caused by a protozoan parasite that is carried by the tsetse fly. The Centers for Disease Control and Prevention (CDC) has provided the following answers to questions about the organism and the disease:
What is West African trypanosomiasis?
There are two types of African trypanosomiasis (also called sleeping sickness); each named for the region of Africa in which it was found historically. Individuals can become infected with West African trypanosomiasis if they receive a bite from an infected tsetse fly, which is only found in Africa. West African trypanosomiasis, also called Gambian sleeping sickness, is caused by a parasite called Trypanosoma brucei gambiense (tri-PAN-o-SO-ma BREW-see-eye GAM-be-ense) carried by the tsetse fly. Approximately 12,000 new cases of West African trypanosomiasis are reported to the World Health Organization each year. However, many cases are not recognized or reported due to a lack of infrastructure and the true number of annual cases is likely to be higher. Cases of West African trypanosomiasis imported into the United States are extremely rare.
How can I get West African trypanosomiasis?
A person gets West African trypanosomiasis through the bite of an infected tsetse fly. Occasionally a pregnant woman may pass the infection to her baby. In theory, the infection can be transmitted through a blood transfusion, but such cases rarely have been documented.
Is West African trypanosomiasis a serious illness?
Yes. West African trypanosomiasis is eventually fatal if it is not treated.
Where can I contract West African trypanosomiasis?
Tsetse flies are found only in Africa and they live in rural environments. West African trypanosomiasis can be contracted in parts of central Africa and in a few areas of West Africa. Most of the reported cases are found in central Africa (Democratic Republic of Congo, Angola, Sudan, Central African Republic, Republic of Congo, Chad, and northern Uganda).
What are the symptoms of West African trypanosomiasis?
Occasionally, within 1 to 3 weeks, the infective bite develops into a red sore, also called a chancre (SHAN-ker). Several weeks to months later, other symptoms of sleeping sickness occur. These include fever, rash, swelling of the face and hands, headaches, fatigue, aching muscles and joints, itching skin, and swollen lymph nodes. Weight loss occurs as the illness progresses. Progressive confusion, personality changes, daytime sleepiness with nighttime sleep disturbances, and other neurologic problems occur after the infection has invaded the central nervous system. These symptoms become worse as the illness progresses. If left untreated, death will eventually occur after several years of infection.
How soon after infection will I have symptoms of 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 have African trypanosomiasis?
If you suspect that you may have West African trypanosomiasis, see your health care provider who will order several tests to look for the parasite. Common tests include examination of blood samples and a spinal tap. Your physician may also take a sample of fluid from swollen lymph nodes.
Is treatment available for West African trypanosomiasis?
Medication for the treatment of West African trypanosomiasis is available. Treatment of West African trypanosomiasis should begin as soon as possible and is based on the infected person’s laboratory results. Hospitalization for treatment is usually necessary. Periodic follow-up exams that include a spinal tap are required for 2 years.
Who is at risk for contracting West African trypanosomiasis?
The tsetse flies that transmit West African trypanosomiasis are found only in rural areas. Travelers to urban areas are not at risk. The flies bite during daylight hours. They inhabit forests and areas of thick vegetation along rivers and waterholes. Even in areas where the disease is present, most flies are not infected with this parasite, so the risk of infection increases with the number of times a person is bitten by the tsetse fly. Therefore, tourists are not at great risk for contracting West African trypanosomiasis unless they are traveling and spending long periods of time in rural areas of central Africa where the disease is present.
Can I take medication to prevent West African trypanosomiasis?
There is neither a vaccine nor recommended drug available to prevent West African trypanosomiasis.
How can I prevent African trypanosomiasis and other insect bites?
- 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.
- Wear neutral-colored clothing. The tsetse fly is attracted to bright colors and very dark colors.
- Inspect vehicles for tsetse flies before entering. The tsetse fly is attracted to moving vehicles.
- Avoid bushes. The tsetse fly is less active during the hottest period of the day. It rests in bushes but will bite if disturbed.
- 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.
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 any questions about the disease described above or think that you may have a parasitic infection, consult a health care provider.
Disclaimer: This article is taken wholly from, or contains information that was originally published by, the Centers for Disease Control and Prevention (CDC). Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the Centers for Disease Control and Prevention (CDC) should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.