American Trypanosomiasis

Introduction

American trypanosomiasis (Chagas disease) is caused by Trypanosoma cruzi, a protozoan parasite found only in the Americas

-it is transmitted to humans by blood-sucking triatomine bugs (kissing bugs, assassin bugs, reduviid bugs)

-it  is endemic in many rural areas of Central and South America and Mexico

-In many countries in South America, Chagas disease is the most important cause of heart disease

Symptoms & Signs 

American trypanosomiasis progresses in 3 stages.

Stage 1 Acute Phase: asymptomatic or fever lymphadenopathy, mild hepatosplenomegaly, and morbilliform/urticarial rash,  a painful inflammatory reaction at the site of inoculation (Chagoma); unilateral conjunctivitis with palpebral edema (Romaña sign)

Stage 2 Indeterminate Phase: asymptomatic but infectious stage 

Stage 3 Symptomatic Chronic Phase: 

CNS: Meningoencephalitis 

Heart: Acute myocarditis, Dilated cardiomyopathy, arrhythmias, congestive heart failure 

GI: Dysphagia, regurgitation, aspiration, constipation, megaesophagus, and megacolon

Diagnosis: Demonstration of trypomastigotes in blood, smooth muscle biopsy, xenodiagnosis, serologic testing, PCR 

Treatment

Medications: Benznidazole, nifurtimox