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Trypanosomiasis- east-African

Overview

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. 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.

Symptoms - Trypanosomiasis- east-African

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.

Causes - Trypanosomiasis- east-African

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.

Prevention - Trypanosomiasis- east-African

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.

Diagnosis - Trypanosomiasis- east-African

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

Microscopic examination of fluid from the original sore at the site of the tsetse fly bite.

Trypanosomes will be present in the fluid for a short period of time following the bite. If the sore has already resolved, fluid can be obtained from swollen lymph nodes for examination. Other methods of trypanosome diagnosis involve culturing blood, lymph node fluid, bone marrow, or spinal fluid. These cultures are then injected into rats, which develop blood-borne protozoa infection that can be detected in blood smears within one to two weeks. However, this last method is effective only for the Rhodesian variety of sleeping sickness.

Prognosis - Trypanosomiasis- east-African

  • In early, or stage 1, trypanosomiasis, most patients experience full recovery following treatment.
  • In late, or stage 2, trypanosomiasis, the CNS manifestations are ultimately fatal if untreated. The cure rate approaches 95% with drugs that work inside the CNS (eg, melarsoprol).

Treatment - Trypanosomiasis- east-African

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.

Only four drugs are registered for the treatment of human African trypanosomiasis: pentamidine, suramin, melarsoprol and eflornithine. However, none of them are anodyne as all have a certain level of toxicity. Pentamidine and suramin are used in the first or early stage of T.b.gambiense and T.b. rhodesiense infections.

Melarsoprol is used in the second or advanced stage of both forms of the disease and eflornithine is only used in the second stage of the T.b.gambiense infections since it has been found not to be effective against the disease due to T.b rhodesiense.

Resources - Trypanosomiasis- east-African

TRAVEL TIPS

African trypanosomiasis is confined to tropical Africa between 15° north latitude and 20° south latitude, or from north of South Africa to south of Algeria, Libya, and Egypt. According to WHO, 25,000-45,000 cases of trypanosomiasis are reported annually; however, the actual prevalence of cases is estimated to be 300,000 to 500,000.

Tsetse flies inhabit rural areas, living in the woodland and thickets of the savannah and the dense vegetation along streams. Infection of international travellers is rare. Approximately 1 case per year is reported among U.S. travellers. Most of these infections are caused by T. b. rhodesiense and they are acquired in East African game parks. Travellers visiting game parks and remote areas should be advised to take precautions. Travellers to urban areas are not at risk.

Since Tsetse flies are only found in rural areas, you can stick to the urban areas of tropical Africa. Insect repellent and light clothing won't help since the Tsetse fly, will bite through everything. Local people will know where the Tsetse flies are likely to be, so ask them and avoid those areas. Tsetse flies are attracted to dark colors and cars. Before you get in to your vehicle, swat the large flies.

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