Health Information

Sleeping sickness

Sleeping sickness


Human African trypanosomiasis

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

I Would Like to Learn About:

  • Causes

    Sleeping sickness is caused byTrypanosoma brucei rhodesiense and Trypanosomoa brucei gambiense. T. b. rhodesiense causes the more severe form of the illness.

    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 be infected.

  • Symptoms

    General symptoms include:

    • Anxiety
    • Mood changes
    • Fever
    • Headache
    • Weakness
    • Insomnia at night
    • Sleepiness during the day (may be uncontrollable)
    • Sweating
    • Swollen lymph nodes all over the body
    • Swollen, red, painful nodule at site of the fly bite
  • Exams and Tests

    A physical exam may show inflammation of the brain and its covering.

    Tests include the following:

    • Blood smear
    • Cerebrospinal fluid tests (fluid from your spinal cord)
    • Complete blood count (CBC)
    • Lymph node aspiration

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

  • Treatment

    Medicines used to treat this disorder include:

    • Eflornithine (for T. b. gambiense only)
    • Melarsoprol
    • Pentamidine (for T. b. gambiense only)
    • Suramin (Antrypol)

    Some people may receive a combination of these medicines.

  • Outlook (Prognosis)

    Without treatment, death can occur within 6 months from cardiac failure or from T. b. rhodesiense infection itself.

    T. b. gambiense infection causes sleeping sickness disease and gets worse quickly, often over a few weeks. The disease needs to be treated immediately.

  • Possible Complications

    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
  • When to Contact a Medical Professional

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

  • Prevention

    Pentamidine injections protect against T. b. gambiense, but not against T. b. rhodesiense. 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.

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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. 8th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2014:chap 279.

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


Review Date: 12/7/2014  

Reviewed By: Jatin M. Vyas, MD, PhD, Associate Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

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