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Test ID: SAM Entamoeba histolytica Antibody, Serum

Reporting Name

E. histolytica Ab, S

Useful For

As an adjunct in the diagnosis of extraintestinal amebiasis, especially liver abscess

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).

Analytic Time

Same day/1 day

Day(s) and Time(s) Performed

Tuesday, Thursday; 9 a.m.

Clinical Reference

1. Bruckner DA: Amebiasis. Clin Microbiol Rev. 1992;5:356-369

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

Method Name

Enzyme-Linked Immunosorbent Assay (ELISA)

Specimen Type

Serum


Advisory Information


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.



Shipping Instructions


 



Specimen Required


Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.5 mL


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.

Test Classification

This test has been cleared, approved or is exempt by the U.S. 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

Forms

If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.

Mayo Clinic Laboratories | Neurology Catalog Additional Information:

mml-CNS-Infections, mml-Pediatric