What are the symptoms of Chagas disease?

Symptoms of Chagas Disease

Chagas disease presents with distinct symptoms across three phases: acute (1-2 months), indeterminate (can last decades), and chronic symptomatic (developing 10-30 years after infection), with cardiac involvement being the most common and serious manifestation. 1

Acute Phase Symptoms (1-2 months after infection)

• Fever
• Malaise
• Facial and lower limb edema
• Generalized lymphadenopathy
• Hepatosplenomegaly
• Entry site signs (chagoma or Romaña's sign - unilateral periorbital swelling)
• Severe manifestations (rare):
  • Myocarditis
  • Meningoencephalitis (particularly in immunosuppressed patients or infants) 1, 2

Most acute infections (>95%) are asymptomatic or present with nonspecific symptoms that often go unrecognized 1, 3.

Indeterminate Phase

• Asymptomatic clinical presentation
• Positive serology for T. cruzi
• Persistent low-grade parasitemia
• No overt organ damage on imaging studies
• May last for decades or for life 1

Approximately 50-70% of infected individuals remain in this phase indefinitely without developing symptomatic disease 1, 4.

Chronic Symptomatic Phase

Approximately 10-30% of infected individuals progress to this phase 10-30 years after initial infection 1, 4.

Cardiac Manifestations (most common and serious)

• Conduction system abnormalities:
  • Right bundle branch block
  • Left anterior fascicular block
  • Complete atrioventricular block
• Structural changes:
  • Segmental left ventricular wall-motion abnormalities
  • Apical aneurysm
  • Progressive LV dilatation and systolic dysfunction
• Arrhythmias:
  • Non-sustained ventricular tachycardia
  • Atrial fibrillation
• Heart failure
• Thromboembolism
• Sudden cardiac death 1, 3, 5

Gastrointestinal Manifestations (15-20% of chronic cases)

• Megaesophagus (causing dysphagia, regurgitation)
• Megacolon (causing constipation, abdominal pain) 1, 4

Neurological Manifestations

• Autonomic nervous system dysfunction (prominent feature)
• Stroke (mainly cardioembolic)
• Peripheral neuropathy 1, 2

Important Clinical Considerations

Diagnostic Approach

Diagnosis is based on:

• Positive serologic tests
• Clinical features consistent with disease phase
• ECG abnormalities
• Imaging studies showing characteristic findings like apical aneurysm 1

Prognosis

• Patients with Chagas cardiomyopathy have a poor prognosis, with 50% mortality within 4 years
• Poor prognostic indicators include:
  • Complete heart block
  • Atrial fibrillation
  • Left bundle branch block
  • Complex ventricular ectopy
  • LV dysfunction
  • Advanced NYHA functional class 1

Treatment Considerations

• Treatment with antiparasitic agents (benznidazole or nifurtimox) is most effective during the acute phase
• Common adverse reactions to benznidazole include:
  • Abdominal pain (25%)
  • Rash (16%)
  • Decreased weight (13%)
  • Headache (7%)
  • Skin lesions
  • Peripheral neuropathy 1, 6

Early detection and treatment are crucial, as treatment efficacy decreases as the disease progresses to the chronic phase 1. However, even with treatment, some patients may still develop cardiac complications 1, 3.