Intact parasite-antigen ELISA test: a new dimension for serodiagnosis of Amoebiasis

Abstract

An Intact Parasite Antigen ELISA (IPA-ELISA) has been developed for detection of circulating antibodies against Entamoeba. histolytica. Axenically grown trophozoites of E.histolytica (NIH-200) after glutaraldehyde treatment, are used as Intact Parasite Antigen (IPA) as well biological active and imperishable base. Antigen over the surface of treated cells were allowed to interact with the antibody molecules of the test sera. The techniques of Plate, Dot-and IPA-ELISA are compared of their merits for clinical and epidemiological survey of amoebiasis. IPA-ELISA was found to be more sensitive (96.8%) and specific (92.3%) in detecting circulating antibodies compared to Plate-ELISA (sensitivity 90.5%, specificity 84.6%) and Do-ELISA (sensitivity 92.1%, specificity 86.1%). The entire IPA-ELISA test could be completed within 3 hours. Costwise IPA-ELISA is several times lesser than Dot-and Plate-ELISA. This test is most suitable for field and clinical trials for suspected cases of amoebiasis with no skilled hand required for diagnosis.