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HelpTest ID SAM Entamoeba histolytica Antibody, Serum
Reporting Name
E. histolytica Ab, SUseful For
As an adjunct in the diagnosis of extraintestinal amebiasis, especially liver abscess
Specimen Type
SerumOrdering Guidance
Direct detection of Entamoeba histolytica in fecal specimens is recommended to diagnose intestinal amebiasis. See OAP / Ova and Parasite, Concentrate and Permanent Smear, Microscopy, Feces or OAPNS / Ova and Parasite, Microscopy, Varies.
Specimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.15 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Frozen (preferred) | 30 days | |
| Refrigerated | 7 days |
Reference Values
Negative
Reference values apply to all ages.
Day(s) Performed
Tuesday, Thursday
Test Classification
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.CPT Code Information
86753
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| SAM | E. histolytica Ab, S | 22285-1 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 9049 | E. histolytica Ab, S | 22285-1 |
Clinical Information
Amebiasis is an infection by the protozoan parasite, Entamoeba histolytica. The infection is acquired by ingestion of cysts in fecally contaminated food or water; excystation and infection occur in the large intestine. After excystation, trophozoites attach to the intestinal wall and liberate extracellular enzymes that enable invasion of the mucosa and spread to other organs, especially the liver and lung where abscesses develop.
Amebiasis (or amebic dysentery) can cause bloody diarrhea accompanied by fever and prostration. White and red blood cells are found in the stool. Liver abscess can develop several weeks to months later producing hepatomegaly and fever.
Pathogenic (E histolytica) and nonpathogenic (Entamoeba dispar) species of Entamoeba occur. Additionally, some of those infected with pathogenic strains are asymptomatic cyst carriers.
Serology may be particularly useful in supporting the diagnosis of amebic liver abscess in patients without a definite history of intestinal amebiasis and who have not spent substantial periods of time in endemic areas.
Interpretation
A positive result suggests current or previous infection with Entamoeba histolytica.
Since pathogenic and nonpathogenic species of Entamoeba cannot be differentiated microscopically, some authorities believe a positive serology indicates the presence of the pathogenic species (ie, E histolytica).
Clinical Reference
1. Bruckner DA: Amebiasis. Clin Microbiol Rev. 1992 Oct;5(4):356-369. doi: 10.1128/CMR.5.4.356
2. Petri WA, Haque R, Moonah SN: Entamoeba species, including amebic colitis and liver abscess. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Elsevier; 2020:3273-3286
Report Available
Same day/1 to 5 daysMethod Name
Enzyme-Linked Immunosorbent Assay (ELISA)
Forms
If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.