A new test for infection by Entamoeba histolytica

Abstract Entamoeba histolytica is a common parasite of the human intestine, and in a significant percentage of cases it invades the tissues. Virulent strains of the organism produce the proteinose histolysain, which almost certainly facilitates the invasive behaviour. Histolysoin has been isolated, a selective assay developed, and specific antisera raised against the enzyme. As described here by Alfredo Luaces, Lyda Osorio and Alan Barren, the ENZYMEBA test for infection by E. histolytica combines the specificities of both antibodies and enzyme assay to achieve a high degree of sensitivity and selectivity. Circulating antibodies to histolysain were detected in a solid-phase enzyme immunoassay, the results suggesting that a humoral immune response is induced by histolysain during the formation of liver abscess.