Sleeping sickness

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


Sleeping sickness is caused by two germs, Trypanosoma brucei rhodesiense and Trypanosomoa brucei gambiense. The more severe form of the illness is caused by T. rhodesiense.

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 is very rare in the United States, and is only found in travelers who have visited or lived in Africa.


General symptoms include:

Exams and Tests

A physical examination 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 very helpful because they cannot tell the difference between current and past infection. Specific IgM levels in the cerebrospinal fluid may be helpful, however.


Medications used to treat this disorder include:

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

Outlook (Prognosis)

Without treatment, death may occur within 6 months from cardiac failure or from T. rhodesiense infection itself. T. gambiense infection causes the classic "sleeping sickness" disease and gets worse more quickly, often over a few weeks. Both diseases should be treated immediately.

Possible Complications

Complications include injury related to falling asleep while driving or performing other activities, and progressive damage to the nervous system. Sleep becomes uncontrollable as the disease gets worse, and eventually leads to coma.

Inflammation of the heart (myocarditis) may develop.

When to Contact a Medical Professional

Call your health care provider if you have symptoms of this disorder. It is important to begin treatment as soon as possible.


Pentamidine injections protect against T. gambiense, but not against T. rhodesiense. Because it is a toxic drug, usuing it for prevention is not recommended.

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

Alternative Names

African trypanosomiasis


Kirchoff LV. Agents of African trypanosomiasis (sleeping sickness). In: Mandell GL, Bennett JE, Dolan R, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 7th ed. Orlando, FL: Saunders Elsevier;2009:chap 278.

Quinn TC. African trypanosomiasis (sleeping sickness). In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 367.

Updated: 4/7/2012

Reviewed by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School, Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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