Coproantigen Versus Classical Microscopy as a Diagnostic Tool for Entamoeba histolytica Infection in the Egyptian Patients

Abstract

Background: Entamoeba histolytica, an amoebic protozoan, is considered as one of the most common causes of nonviral (Parasitic) diarrheal illness in humans. Laboratory diagnosis consists primarily of direct microscopic examination of stool specimen for both trophozoites and cysts. However, because of the intermittent fecal excretion of the parasite, the case may be mis-diagnosed and the patient may continue excreting the parasite and infecting others. That is why other methods of diagnosis should be looked for that can help overcome the defects and drawbacks of microscopy when used alone for diagnosis. Aim of the work: the current study aimed to evaluate the efficacy of coproantigen detection by ELISA test in comparison with direct microscopy in diagnosis of E. histolytica/dispar in stool specimens from patients with diarrhea and other gastrointestinal symptoms. Material and Methods: stool samples were collected form 250 children included in the present study (150 symptomatic and 100 asymptomatic groups) between the ages of 1 and 10 years and subjected to direct microscopic examination and ELISA test for coproantigen detection. Results: out of 250 stool samples, 64 specimens (25.6%) were positive for E. histolytica/dispar by direct microscopy, while 79 specimens (31.6%) were positive by ELISA test. The sensitivity and specificity of ELISA test compared to direct microscopy were found to be 96.9% and 90.9%, respectively. Conclusion: ELISA test for coproantigen detection in stool samples is a rapid and effective method with high sensitivity and specificity for diagnosis of amoebiasis in stool specimens even when the parasitic count is low, thus reducing the chances of missing positive cases even in the asymptomatic cases.