American Trypanosomiasis (Trypanosomiasis)

American Trypanosomiasis (Chagas Disease) – Treatment Overview

Introduction
American trypanosomiasis, commonly known as Chagas disease, is caused by the protozoan parasite Trypanosoma cruzi, transmitted primarily by triatomine bugs (“kissing bugs”). It is endemic in Latin America but increasingly detected worldwide due to migration. The disease has two phases:

• Acute phase: Often asymptomatic or mild (fever, malaise, lymphadenopathy, hepatosplenomegaly, Romaña’s sign – periorbital swelling). Parasitemia is high.

• Chronic phase: May remain indeterminate (asymptomatic) or progress to cardiac complications (arrhythmias, cardiomyopathy, heart failure) and gastrointestinal disease (megaesophagus, megacolon).

Treatment aims to eradicate the parasite in acute and early chronic infection, slow disease progression, and manage organ complications.

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Antiparasitic Therapy

1. Benznidazole (first-line therapy)

• Adults: 5–7 mg/kg/day orally in 2 divided doses for 60 days.

• Children: 5–10 mg/kg/day orally in 2–3 divided doses for 60 days.

• Side effects: Rash, neuropathy, gastrointestinal upset, bone marrow suppression (rare).

2. Nifurtimox (alternative)

• Adults: 8–10 mg/kg/day orally in 3–4 divided doses for 60–90 days.

• Children: 15–20 mg/kg/day (infants/young children) or 12.5–15 mg/kg/day (older children) for 60–90 days.

• Side effects: GI upset, weight loss, irritability, insomnia, neuropathy.

Notes:

• Both drugs are most effective in acute and early chronic infection.

• Effectiveness in late chronic disease is limited, but may still slow progression, especially in younger patients.

• Contraindicated in pregnancy and severe hepatic/renal disease.

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Supportive and Symptomatic Treatment (Chronic Phase)

Cardiac involvement

• Antiarrhythmics: Amiodarone 200–400 mg daily for ventricular arrhythmias.

• Pacemaker/ICD: For advanced conduction defects or life-threatening arrhythmias.

• Heart failure management: ACE inhibitors/ARBs, beta-blockers, diuretics, aldosterone antagonists.

• Heart transplantation: Option in end-stage cardiomyopathy.

Gastrointestinal involvement

• Dietary modifications and laxatives for constipation.

• Surgical correction for megacolon or megaesophagus if severe.

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Preventive Measures

• Vector control (insecticide spraying, improved housing).

• Screening of blood donors, organ donors, and pregnant women in endemic regions.

• Congenital transmission prevention through maternal screening and early treatment of infected infants.