Trypanosomiasis

Introduction

Human African trypanosomiasis (HAT) or African sleeping sickness is a serious infection caused by a protozoan called Trypanosoma 

-the organisms are transmitted by bites of tsetse flies, which are confined to Central Africa  

-the disease is divided into West and East African forms

-Trypanosoma brucei gambiense causes West African sleeping sickness (95% of cases)

-Trypanosoma brucei rhodesiense causes East African sleeping sickness (5% of cases) 

Symptoms & Signs 

-a painful chancre develops at the site of the tsetse bite 

-It consists of a circumscribed, rubbery, indurated, dusky red nodule, often with a central eschar 

-Fever, headache, myalgia, lymphadenopathy, disseminated intravascular coagulopathy, QTc prolongation,pulmonary edema, ARDS, hypotension, and shock

-Involvement of the posterior cervical (Winterbottom sign) and supraclavicular lymph node in Gambian trypanosomiasis

Diagnosis 

Diagnosis is by detection of trypanosomes in blood films, Giemsa-stained thick smears, chancre, lymph node aspirate, bone marrow or CSF 

Treatment 

-Lumbar puncture must always be performed before initiation of therapy for sleeping sickness

-Selection of drugs dependent on whether CNS is involved

-CNS is not invaded: pentamidine, suramin

-CNS is invaded:  eflornithine, nifurtimox, melarsoprol, and fexinidazole 

Prognosis: Without CNS involvement, recovery often complete

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