Entamoeba histolytica – Abscess Liver

Specimen Collection and Handling

Specimen Requirements

Test Requested Required Requisition(s) Specimen Type Minimum Volume Collection Kit

Entamoeba histolytica

Aspirated material or pus3

0.5 ml

Parasitology Kit Order #390033 AND Sterile container

Entamoeba histolytica

Aspirated material from a sterile site

0.5 ml

Parasitology Kit Order #390033 AND Sterile container

Submission and Collection Notes

1

Please note on the requisition (under other): If the patient has Eosinophilia, HIV, is immunocompromised, has a Critical illness or was admitted to ICU, or had a previous parasitic infection.

2

Indicate Country/Region and if the patient is a new immigrant or refugee or returned traveler under ‘Travel’ section of the requisition.

3

Collect from edge or base of abscess in liver, skin, bowel, etc.

Preparation Prior to Transport

Label the specimen container with the patient’s full name, date of collection and one other unique identifier such as the patient’s date of birth or Health Card Number. Failure to provide this information may result in rejection or testing delay.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

Entamoeba histolytica testing is performed Monday to Friday.

Turnaround time is up to 3 days from receipt by the PHO laboratory.

Reporting

Results are reported to the ordering physician or health care provider as indicated on the requisition.

Test Methods

Specimens are examined by microscopy by preparing a smear and concentrate following a centrifugation procedure using the Formalin/Ethyl-acetate method. The concentration method allows for detection of small numbers of organisms.

It has been established that Entamoeba histolytica is morphologically identical to the non-pathogen Entamoeba dispar.

Only Entamoeba histolytica is capable of tissue invasion and causing an amoebic liver abscess.

Algorithm

An ELISA based fecal antigen is used as the standard reference method at PHO laboratories to differentiate the two species.

This test is only performed as follow up test based on microscopy of an SAF-preserved faecal specimen, but can be requested for liver abscess fluid as well. 

Note: The test will only be performed following a positive microscopy for E. histolytica/dispar on an SAF preserved specimen. The test will not be performed if the patient is being treated for an Entamoeba infection or as a follow up specimen following treatment.

Mis à jour le 4 janv. 2019