Trypanosoma cruzi - Chagas Disease

Chagas disease or American trypanosomiasis is caused by Trypanosoma cruzi, a protozoan transmitted by infected Triatominae insects. Diagnosis is generally made by testing with at least two different serologic tests; IgG confirms chronic disease.

Tabs Content

Clinical Overview

Diagnosis

Indications for Testing

Residency in endemic area
Recent travel to endemic area
Cardiomyopathy or prototypical gastrointestinal disease without obvious etiology

Laboratory Testing

Trypanosomiasis diagnosis (CDC, 2014)
Acute phase (first 60-90 days)
- Direct detection of parasites on blood smear (Giemsa stain)
- IgM may be useful in acute infection
- Polymerase chain reaction (PCR) is very sensitive when available
Nonacute (chronic) phase (>90 days)
- IgG confirms chronic disease – by indirect fluorescent antibody (IFA), enzyme-linked immunosorbent assay (ELISA), or indirect hemagglutination antibody (IHA)
  - World Health Organization (WHO) recommends at least two tests to confirm disease
- Cross-reactivity with Leishmania spp may occur
- PCR requires further validation

Differential Diagnosis

Muscular disease
- Trichinella spiralis infection
- Inflammatory myopathies
Cardiomyopathy
- High-output failure
  - Anemia
  - Beriberi
  - Paget disease
  - Hyperthyroidism
- Acute rheumatic fever
- Valvular disease
- Congenital heart disease
- Acute myocarditis
Megaesophagus
- Achalasia
- Strictures
- Esophageal cancer
Megacolon
- Hirschsprung disease
- Diabetic gastroenteropathy
- Colonic stricture
- Systemic sclerosis
- Amyloidosis
Neurologic disease
- Myotomic dystrophy
- Parkinson disease
- Chronic opiate ingestion
- Severe hyperthyroidism

Background

Epidemiology

Prevalence
- U.S. – almost exclusively found in immigrants from Central and South America
- Worldwide – 16-18 million individuals infected
Transmission
- Triatominae vector species (kissing bug)
- Maternal transplacental transfer (congenital)
- Blood transfusion from infected donor
- Organ transplantation
- Ingestion of contaminated food/water (rare)

Organism

The genus Trypanosoma contains many species of protozoans
- Only three cause human disease – T. cruzi, T. brucei gambiense, and T. brucei rhodesiense
- Vectorborne from the reduviid Triatoma gerstaeckeri and others
  - Exposure to feces deposited on skin by infected bugs

Clinical Presentation

Acute phase
- Mild symptoms occur for 2 weeks to 3 months
  - Romaña sign – unilateral painless edema of palpebral and periocular tissues
- Initial signs include malaise, fever, anorexia, rash, and edema
- Acute myocarditis in small percentage of cases
- Indurated area of erythema and swelling (chagoma) may indicate parasite entry site
- Frequently undetected at this stage
Chronic phase
- May manifest decades later
- Cardiomyopathy with arrhythmia
  - ~20-30% of patients (Bern, 2015)
  - Earliest sign is conduction defects – patient usually asymptomatic
  - Symptoms of biventricular failure – peripheral edema, hepatomegaly
  - ~60% experience sudden cardiac death
- Digestive system complications
  - Megacolon
  - Ranges from mild achalasia to megaesophagus
Congenital disease
- Highest risk for infection when maternal parasitemia is high during acute phase
- Prematurity, hepatosplenomegaly, meningitis/encephalitis
Immunocompromised hosts
- Organ transplant recipients – more severe clinical spectrum that can include acute myocarditis and congestive heart failure
- Immunocompromised patient with reactivation – most common presentations are meningoencephalitis, brain abscess, and acute myocarditis

ARUP Lab Tests

Tests generally appear in the order most useful for common clinical situations. Click on number for test-specific information in the ARUP Laboratory Test Directory.

Parasites Smear (Giemsa Stain), Blood 0049025
Method: Stain

Recommended Use

Screen for and detect spirochetes and blood parasites, including microfilaria, Babesia, Trypanosoma, and Plasmodium species

Patient's travel history is necessary to aid in test interpretation

Trypanosoma cruzi Antibody, IgM 0051075
Method: Semi-Quantitative Indirect Fluorescent Antibody

Recommended Use

Aid in the diagnosis of Chagas disease (T. cruzi); may be useful in acute phase of disease

Order in conjunction with blood parasite screen

Trypanosoma cruzi Antibody, IgG 0051076
Method: Semi-Quantitative Enzyme-Linked Immunosorbent Assay

Recommended Use

Aid in the diagnosis of nonacute (chronic phase) Chagas disease (T. cruzi)

Follow-up

If test results are equivocal, repeat testing in 10-14 days

Medical Experts

Couturier, Marc Roger, PhD, D(ABMM), Medical Director, Microbial Immunology, Parasitology and Fecal Testing, and Infectious Disease Antigen Testing at ARUP Laboratories; Associate Professor of Clinical Pathology, University of Utah

Slev, Patricia R., PhD, Laboratory Section Chief, Immunology, at ARUP Laboratories; Associate Professor of Clinical Pathology, University of Utah

References

General References

Bern C, Montgomery SP, Herwaldt BL, Rassi A, Marin-Neto JA, Dantas RO, Maguire JH, Acquatella H, Morillo C, Kirchhoff LV, Gilman RH, Reyes PA, Salvatella R, Moore AC. Evaluation and treatment of chagas disease in the United States: a systematic review. JAMA. 2007; 298(18): 2171-81. PubMed

Bern C. Chagas' Disease. N Engl J Med. 2015; 373(5): 456-66. PubMed

Hemmige V, Tanowitz H, Sethi A. Trypanosoma cruzi infection: a review with emphasis on cutaneous manifestations. Int J Dermatol. 2012; 51(5): 501-8. PubMed

Lescure F, Le Loup G, Freilij H, Develoux M, Paris L, Brutus L, Pialoux G. Chagas disease: changes in knowledge and management. Lancet Infect Dis. 2010; 10(8): 556-70. PubMed

Rassi A, Rassi A, de Rezende JM. American trypanosomiasis (Chagas disease). Infect Dis Clin North Am. 2012; 26(2): 275-91. PubMed

Woodhall D, Jones JL, Cantey PT, Wilkins PP, Montgomery SP. Neglected parasitic infections: what every family physician needs to know. Am Fam Physician. 2014; 89(10): 803-11. PubMed

Resources from the ARUP Institute for Clinical and Experimental Pathology®

Malan AK, Avelar E, Litwin SE, Hill HR, Litwin CM. Serological diagnosis of Trypanosoma cruzi: evaluation of three enzyme immunoassays and an indirect immunofluorescent assay. J Med Microbiol. 2006; 55(Pt 2): 171-8. PubMed

Last Update: July 2018

Trypanosoma cruzi - Chagas Disease

Diagnosis

Indications for Testing

Laboratory Testing

Differential Diagnosis

Background

Epidemiology

Organism

Clinical Presentation

ARUP Lab Tests

Medical Experts

References

General References

Resources from the ARUP Institute for Clinical and Experimental Pathology®

ARUP Laboratories

ARUP Websites

ARUP Consult


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	Trypanosoma cruzi - Chagas Disease. ARUP Consult^©. Retrieved April 17, 2019, from: https://arupconsult.com/content/trypanosoma-cruzi

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Trypanosoma cruzi - Chagas Disease

Diagnosis

Indications for Testing

Laboratory Testing

Differential Diagnosis

Background

Epidemiology

Organism

Clinical Presentation

ARUP Lab Tests

Medical Experts

References

General References

Resources from the ARUP Institute for Clinical and Experimental Pathology®

ARUP Laboratories

ARUP Websites

ARUP Consult