Sleeping sickness


Sleeping sickness is infection with germs carried by certain flies. It results in swelling of the brain.

Alternative Names

Human African trypanosomiasis

Causes, incidence, and risk factors

Sleeping sickness is caused by two germs (protozoa), and . The more severe form of the illness is caused by .

Tsetse flies carry the infection. When an infected fly bites you, the infection spreads through your blood.

Risk factors include living in parts of Africa where the disease is found and being bitten by tsetse flies. The disease does not occur in the United States. But travelers who have visited or lived in Africa can have the infection.


General symptoms include:

Signs and tests

A physical exam may show signs of inflammation of the brain and its covering, the meninges (meningoencephalitis).

Tests include the following:

Most antibody and antigen tests are not helpful because they cannot tell the difference between current and past infection. Specific IgM levels in the cerebrospinal fluid may be more helpful.


Medicines used to treat this disorder include:

  • Eflornithine (for only)
  • Melarsoprol
  • Pentamidine (for only)
  • Suramin (Antrypol)
  • Some patients may receive combination therapy

Support Groups

Expectations (prognosis)

Without treatment, death can occur within 6 months from cardiac failure or from infection itself. infection causes the classic sleeping sickness disease and gets worse more quickly, often over a few weeks. Either disease needs to be treated immediately.


Complications include:

  • Injury related to falling asleep while driving or during other activities
  • Gradual damage to the nervous system
  • Uncontrollable sleep as the disease gets worse
  • Coma

Calling your health care provider

See your health care provider right away if you have symptoms. It is important to begin treatment as soon as possible.


Pentamidine injections protect against But not against . Because this medicine is toxic, using it for prevention is not recommended.

Insect control measures can help prevent the spread of sleeping sickness in high-risk areas.


Kirchoff LV. Agents of African trypanosomiasis (sleeping sickness). In: Mandell GL, Bennett JE, Dolan R, eds. . 7th ed. Philadelphia, PA: Elsevier Churchill-Livingstone; 2009:chap 278.

Petri Jr WA. African sleeping sickness. In: Goldman L, Schafer AI, eds. . 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 354.


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