5-52
heavy infestations
Probable Mode of Transmission: Ingestion of embryonated eggs
ID: African Trypanosomiasis (Sleeping Sickness)
LTC Glenn Wortmann, MC, USAIntroduction: Transmitted by tsetse fly bites, infection with Trypanosoma brucei may cause either West
African (T. brucei gambiense) or East African (T. brucei rhodesiense) trypanosomiasis. Sleeping sickness is
endemic in 36 African countries. In the more rapidly progressive T.b. rhodesiense infection the incubation
period is 3 days to a few weeks, in T.b. gambiense the incubation period may last several months to years.
Subjective: Symptoms
A painful trypanosomal chancre may develop at the site of the tsetse fly bite.
West African: Fever develops weeks to months after the bite, followed by lymphadenopathy. Personality
changes, intense headache and difficulty walking eventually occur. The final phase is marked by progressive
neurologic impairment ending in coma and death.
East African: The onset of symptoms usually occurs more rapidly, with fever, malaise and headache
occurring within a few days to weeks. Lymph node swelling is not as common. Without treatment, death
usually occurs within weeks to months.
Focused History: Do you remember a painful insect bite? (The tsetse fly bite is usually painful.) Have you
noticed a rash? (A rash is common with East African disease.) When might have you been exposed to a
tsetse fly? (The incubation period for East African disease is usually a few days, while that for West African
disease is weeks to months.)
Objective: Signs
Fever; tachycardia; painless, enlarged lymph nodes; painful chancre at bite site with surrounding edema.
Using Advanced Tools: Trypanosomes may be seen on examination of thick and thin peripheral blood
smears. (see Color Plates Picture 32)
Assessment: Diagnose by identifying organism on blood smear.
Differential Diagnosis: Fever - many other diseases can cause similar symptoms, including tuberculosis
and malaria. A history of travel to an area endemic for African Trypanosomiasis should prompt a diagnostic
evaluation for that disease.
Altered mental status - meningitis, brain abscess
Plan:
Treatment: Requires evacuation to a medical center with infectious disease and tropical medicine support
for definitive diagnosis and treatment. For patients without evidence of CNS infection (examine the
cerebrospinal fluid), treatment with suramin is suggested. For CNS infection with East African disease,
melarsoprol is recommended, while CNS infection with West African disease requires treatment with
eflornithine.
Patient Education
General: Avoid tsetse fly bites by wearing protective clothing.
Activity: As tolerated
Diet: As tolerated.
Medications: Since medications have several severe side effects, they should only be given at a tertiary
care center.