Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 35-01: African Trypanosomiasis (Sleeping Sickness) + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ Exposure to tsetse flies Hemolymphatic disease: Irregular fever, headache, joint pain, rash, edema, lymphadenopathy Meningoencephalitic disease: Somnolence, severe headache, progressing to coma Trypanosomes in blood or lymph node aspirates; positive serologic tests Trypanosomes and increased white cells and protein in cerebrospinal fluid +++ General Considerations ++ African trypanosomiasis is caused by the hemoflagellates Trypanosoma brucei rhodesiense and Trypanosoma brucei gambiense The organisms are transmitted by bites of tsetse flies (genus Glossina), which inhabit shaded areas along streams and rivers Trypanosomes ingested in a blood meal undergo a developmental period of 18–35 days in the fly When the fly feeds again on a new mammalian host, the infective stage is injected T b rhodesiense causes East African trypanosomiasis, and is transmitted in the savannas of east and southeast Africa T b rhodesiense infection is primarily a zoonosis of game animals and cattle; humans are infected sporadically +++ Demographics ++ Total incidence has been estimated at < 5000 cases per year, mostly due to T b gambiense, with the largest number in the Democratic Republic of the Congo Infections are rare among travelers, including visitors to game parks + Clinical Findings Download Section PDF Listen +++ ++ Chancres at the bite site; lesion is painful and measures 3–10 cm Symptom onset usually occurs within a few days of the insect bite The hemolymphatic stage includes intermittent fever and rash, but lymphadenopathy is less common than with West African disease Myocarditis can cause tachycardia and death due to arrhythmias or heart failure + Diagnosis Download Section PDF Listen +++ ++ Microscopic examination of fluid expressed from a chancre or lymph node may show motile trypanosomes or, in fixed specimens, parasites stained with Giemsa During the hemolymphatic stage, detection of parasites in Giemsa-stained blood smears is common Serial specimens should be examined, since parasitemias vary greatly over time Meningoencephalitic (or second stage) disease is defined by the World Health Organization as cerebrospinal fluid (CSF) showing at least five mononuclear cells per microliter, elevated protein, or presence of trypanosomes Concentration techniques can aid identification of parasites in blood or CSF Serologic tests are also available Field-applicable immunochromatographic lateral flow rapid diagnostic tests that cost less than CATT and are simpler to perform are available Combining tests improves sensitivity and specificity Molecular diagnostic tests, including PCR and field-friendly loop-mediated isothermal amplification (LAMP) are available, but these are not yet standardized or routinely available + Treatment Download Section PDF Listen +++ ++ Pentamidine and eflornithine are not reliably effective Suramin Used to treat early disease Dosing regimens vary: 100–200 mg test dose, then 20 mg/kg (maximum 1 g) intravenously on days 1, 3, 7, 14, and 21 or weekly for five doses Toxicities include vomiting and, rarely, seizures and shock during infusions as well as subsequent fever, rash, headache, neuropathy, and kidney and bone marrow dysfunction Melarsoprol Used for CNS infection since suramin does not enter CNS Dosage: three series of 3.6 mg/kg/day intravenously for 3 days, with 7-day breaks between the series or a 10-day intravenous course with 0.6 mg/kg on day 1, 1.2 mg/kg on day 2, and 1.8 mg/kg on days 3–10) Immediate side effects include fever and gastrointestinal symptoms Most important side effect is a reactive encephalopathy Can progress to seizures, coma, and death To help avoid this side effect, corticosteroids are coadministered (dexamethasone 1 mg/kg/day intravenously for 2–3 days or oral prednisolone 1 mg/kg/day for 5 days, and then 0.5 mg/kg/day until treatment completion) In addition, increasing resistance to melarsoprol is a serious concern + Outcome Download Section PDF Listen +++ +++ Prognosis ++ If untreated, progresses over weeks to months to meningoencephalitic disease, somnolence, coma, and death +++ Prevention ++ Individual prevention should include Wearing neutral-colored clothes with long sleeves and pants Insect repellents Using mosquito nets while sleeping Control programs focusing on vector elimination and treatment of infected persons and animals have shown good success but suffer from limited resources + References Download Section PDF Listen +++ + +Aksoy S et al. Human African trypanosomiasis control: achievements and challenges. PLoS Negl Trop Dis. 2017 Apr 20;11(4):e0005454. [PubMed: 28426685] + +Büscher P et al. Human African trypanosomiasis. Lancet. 2017 Nov 25;390(10110):2397–409. [PubMed: 28673422]