DETECTION OF ENTAMOEBA-HISTOLYTICA AND E-DISPAR DIRECTLY IN STOOL

Current diagnosis of Entamoeba histolytica infection requires the dire ct microscopic identification of the parasite, a technique that is ins ensitive and cannot distinguish pathogenic E. histolytica from noninva sive E. dispar. Enzyme-linked immunosorbent assay (ELISA) antigen defe ction tests were developed to distinguish E. histolytica from E. dispa r infection in stool specimens. The ELISA result for E. histolytica an tigen was positive in 26 of 27 E. histolytica-positive stool specimens , three of 25 E. dispar-positive stools, and one of 30 stools with oth er or no intestinal parasites, giving a specificity and sensitivity fo r the detection of E. histolytica infection of 93% and 96%, respective ly. The assay result used to detect both E. dispar and E. histolytica was positive in 26 of 27 E. histolytica-positive stools, 19 of 25 E. d ispar-positive stools, and one of 30 stools negative dy microscopy and culture for Entamoeba, giving a specificity and sensitivity of 97% an d 87%, respectively. Because these ELISAs can be completed in several hours, they offer promise as rapid and sensitive means of detecting am ebic infection.