Diagnosis of chronic Trypanosoma cruzi infection (Chagas disease)
Enzyme-Linked Immunosorbent Assay (ELISA)
CHAGS
American trypanosomiasis
Chagas
Chagas disease
Kissing bug
Reduviid
T. cruzi
Triatoma
Trypanosoma
Trypanosomiasis
Serum
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.7 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.
0.6 mL
Gross hemolysis | Reject |
Gross lipemia | Reject |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Frozen | 14 days |
Diagnosis of chronic Trypanosoma cruzi infection (Chagas disease)
Chagas disease (American trypanosomiasis) is an acute and chronic infection caused by the protozoan hemoflagellate Trypanosoma cruzi. T cruzi is endemic in many areas of South and Central America. The parasite is usually transmitted by the bite of reduviid (or "kissing") bugs of the genus Triatoma but may also be transmitted by blood transfusion, organ transplantation, food ingestion, and vertically from mother to fetus. The acute febrile infection is frequently undiagnosed and often resolves spontaneously. Diagnosis of acute T cruzi infection is most frequently confirmed by microscopic identification of trypomastigotes in fresh preparations of anticoagulated blood or buffy coat or by molecular detection. Parasitemia decreases and is undetectable within approximately 90 days of infection.
Chronic T cruzi infections are often asymptomatic but may progress to produce disabling and life-threatening cardiac (cardiomegaly, conduction defects) and gastrointestinal (megaesophagus and megacolon) disease. These damaged tissues contain the intracellular amastigote of T cruzi. The parasite is not seen in the blood during the chronic phase. Diagnosis of chronic T cruzi infection relies on serologic detection of antibodies to this organism. However, no single serologic assay is sensitive and specific enough to be relied upon alone. Therefore, per current guidelines and the Centers of Disease Control and Prevention, serologic confirmation of chronic T cruzi infection requires positivity on 2 tests utilizing 2 different methodologies or 2 different T cruzi antigen preparations. When results are discordant, testing by a third assay is recommended to resolve the initial results or, alternatively, repeat testing on a new sample may be required.
Negative
Reference values apply to all ages.
False-positive results may occur in patients infected with Leishmania or other Trypanosoma species, including Trypanosoma rangeli.
Diagnosis of chronic Chagas disease requires both clinical evaluation (including exposure history) and laboratory testing. Chagas disease should not be diagnosed based on a single serologic result alone.
A single negative result does not exclude the diagnosis of Chagas disease as antibodies to the pathogen may not yet be detectable. Sensitivity of the assay may be decreased in significantly immunosuppressed patients.
1. Bern C, Montgomery SP, Herwaldt BL, et al: Evaluation and treatment of Chagas disease in the United States: A Systematic Review. JAMA. 2007 Nov 14;298(18):2171-2181
2. Bern C, Messenger LA, Whitman JD, Maguire JH: Chagas disease in the United States: a public health approach. Clin Microbiol Rev. 2019 Nov 27;33(1):e00023-19. doi: 10.1128/CMR.00023-19
Monday
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
86753
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
CHAGS | T. cruzi Total Ab, EIA, S | 57320-4 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
CHAGS | T. cruzi Total Ab, EIA, S | 57320-4 |
Change Type | Effective Date |
---|---|
Obsolete Test | 2025-01-23 |