Entamoeba histolytica Antigen Test

 


1. Objective

To detect the presence of Entamoeba histolytica-specific antigens in a stool specimen for the diagnosis of amoebiasis, especially in symptomatic patients.

2. Principle

The test is typically based on an immunoassay technique such as:

  • Enzyme-Linked Immunosorbent Assay (ELISA)

  • Lateral Flow Immunochromatographic Test (ICT)

These methods use antibodies specific to E. histolytica antigens to detect the presence of parasite components in stool. This distinguishes E. histolytica (pathogenic) from non-pathogenic E. dispar and E. moshkovskii.

3. Materials

  • Fresh or preserved stool sample

  • E. histolytica antigen test kit (ICT or ELISA type)

  • Sample diluent/extraction buffer

  • Test strip or microplate wells

  • Dropper or pipette

  • Timer

  • PPE (gloves, mask, etc.)

4. Procedure (Lateral Flow/ICT Example)

  1. Collect stool sample in a clean container.

  2. Add a small amount (e.g., 50–100 mg) of stool into the extraction buffer.

  3. Mix thoroughly to create a homogenous solution.

  6. Add 2–3 drops of the prepared sample into the sample well of the test device.

  7. Wait 10–15 minutes.

  8. Read the results based on control (C) and test (T) lines.

5. Result Interpretation

Line Pattern Interpretation
C line only Negative for E. histolytica antigen
C + T lines Positive (antigen detected)
No C line Invalid test (repeat required)


6. Uses

  • Diagnose intestinal amoebiasis (amoebic dysentery)

  • Differentiate E. histolytica from E. dispar

  • Useful when microscopy is inconclusive or unavailable

  • Suitable for fieldwork and point-of-care diagnosis

7. Conclusion

The Entamoeba histolytica antigen test offers a rapid, specific, and non-invasive diagnostic option for amoebiasis. It improves diagnostic accuracy over microscopy by detecting only the true pathogenic species.

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