African Trypanosomiasis (sleeping sickness)

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What is African trypanosomiasis (sleeping sickness)?

African trypanosomiasis, also known as sleeping sickness, is a disease spread by an infected tsetse fly. The tsetse fly is found in some rural areas of sub-Saharan Africa.

Without treatment, sleeping sickness is fatal.

Cause 

  • Sleeping sickness is caused by two different parasites, Trypanosoma brucei rhodesiense and Trypanosoma brucei gambiense.
  • The most reported cases of sleeping sickness are caused by T. b. gambiense.

Risk to Travellers     

  • Risk for most travellers is low.
  • Risk is higher for travellers who are:
    • visiting or living in rural areas
    • visiting game parks or other areas with thick vegetation or forests

Severity

  • The disease eventually affects the central nervous system, causing confusion, daytime sleepiness, and personality changes.
  • Without treatment, sleeping sickness is fatal.
  • The symptoms caused by T. b. rhodesiense become severe more quickly than the symptoms caused by T. b. gambiense. 

Prevention

  • There is no vaccine or medication that can prevent sleeping sickness, so preventing tsetse fly bites is the best way to prevent this disease.
    • Avoid areas with heavy infestations of tsetse flies.
    • Wear light-coloured pants and long-sleeved shirts.
  • Avoid blood transfusions in areas where sleeping sickness occurs, if at all possible.

Treatment

  • Treatment is available.
  • Tsetse fly bites are painful. If you are bitten and you develop a fever or any other symptoms of sleeping sickness, seek medical attention as soon as possible.

Symptoms

The symptoms of sleeping sickness differ depending on whether the infection is due to T. b. rhodesiense or T. b. gambiense.

Symptoms of T. b. rhodesiense infection:

  • Symptoms usually appear from three days to a few weeks after the bite from an infected tsetse fly and may include:
    • painful chancre (small ulcer) at the site of the infected tsetse fly bite
    • high fever
    • severe headache and muscle aches
    • rash
  • Less commonly, enlargement of the spleen, kidney problems, or heart problems can develop.
  • Neurological symptoms, like sleep disturbances, poor coordination, and personality changes, develop within a few weeks or months of initial infection.
  • If untreated, T. b. rhodesiense infection is usually fatal within weeks or months.

Symptoms of T. b. gambiense infection:

  • Symptoms usually appear months or even years after the bite from an infected tsetse fly.
  • Symptoms of T. b. gambiense infection are often non-specific, such as:
    • fever
    • headache and muscle aches
    • itchiness
    • swelling of the face
    • swollen lymph nodes
    • weight loss
  • Neurological symptoms, like sleep disturbances, poor coordination, and personality changes, develop months after the initial infection.
  • If untreated, T. b. gambiense infection is usually fatal within several years.

Transmission

  • Sleeping sickness is most commonly spread through the bite of an infected tsetse fly.
    • A human becomes infected with Trypanosoma brucei parasites when an infected tsetse fly feeds on his or her blood.
    • Tsetse flies are only found in sub-Saharan Africa. They are the size of a honey bee and are grey-brown.
    • Tsetse flies usually bite during the daytime and their bites are usually quite painful.
  • The parasites that cause sleeping sickness, especially T. b. rhodesiense, can also infect cattle and wild animals.
  • Rarely, sleeping sickness can also be spread:
    • through a blood transfusion from an infected donor
    • from an infected mother to her baby during pregnancy or delivery

Where is African trypanosomiasis (sleeping sickness) a concern?

  • Sleeping sickness is transmitted by tsetse flies in rural sub-Saharan Africa.
  • T. b. rhodesienseis found in eastern and southern Africa.
    • Most cases of T. b. rhodesiense infection occur in Malawi, Tanzania, Uganda, and Zambia.
  • T. b. gambienseis found in central Africa and in some areas of western Africa.
    • Most cases of T. b. gambiense infections occur in Angola, Central African Republic, Chad, the Democratic Republic of Congo, Sudan, and Uganda.

Recommendations for travellers

Consult a doctor, nurse or health care provider, or visit a travel health clinic preferably six weeks before you travel.

  1. Protect yourself from tsetse fly bites.  
    • Avoid areas with heavy infestations of tsetse flies.
    • Cover up:
      • Wear long-sleeved, tucked-in shirts, long pants, shoes or boots (not sandals), and a hat.
      • Tsetse flies can bite through lightweight fabric. Wear heavier fabrics.
      • Tsetse flies are attracted by bright and dark colours. Wear light-coloured clothing or neutral colors that blend with the environment.
    • Information about the effectiveness of DEET and icaridin insect repellents and permethrin insecticide-treated clothing in preventing tsetse fly bites are limited. These are still options to consider, however, especially because the areas where sleeping sickness occurs overlap with areas where other insect-borne diseases like malaria. 
  2. In areas where sleeping sickness occurs, avoid blood transfusions unless it is an emergency.
    • If you must receive a blood transfusion while travelling, try to ensure the donated blood has been tested for sleeping sickness.
    • If you cannot ensure the blood has been screened, and you do not require emergency care, return home for treatment.
  3. Know the symptoms of sleeping sickness and see a health care provider if they develop.
    • Symptoms of sleeping sickness may develop months after visiting a region where the disease occurs.
    • Tell your healthcare provider that you have travelled to a region where sleeping sickness occurs.

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