EVALUATION OF 3 SEROLOGICAL TESTS FOR THE DETECTION OF ANTIAMEBIC ANTIBODIES APPLIED TO SERA OF PATIENTS FROM AN AREA ENDEMIC FOR AMEBIASIS

Two enzyme immuno assays based on a single recombinant Entamoeba histo lytica antigen (P1-EIA) or soluble E. histolytica extract (SA-EIA) as well as a latex agglutination test using an E. histolytica membrane fr action (M-LA) were evaluated for its use to detect anti-amebic serum a ntibodies in patients from Durban, South Africa, an area endemic for a mebiasis. In a previous study, all three test systems were found to be reliable in terms of sensitivity and specificity when applied to sera of European individuals. By analysing a total of 167 serum samples of patients from the Durban area, suffering from invasive amebiasis (n = 76) or miscellaneous diseases unrelated to E. histolytica infection ( n = 91), the present study revealed sensitivity for the detection of a nti-amebic antibodies of 97.4% for SA-EIA, 86.8% for P1-EIA and 96.1% for M-LA, respectively. Specificity was high for P1-EIA (96.7%) and M- LA (92.3%) but substantially lower for SA-EIA (62.6%). In addition, an tibody responses to the recombinant P1 antigen were analysed in 16 pat ients with amebic liver abscess before and after anti-amebic treatment . The results indicated that most of the patients lost their specific antibody response within 7 month of follow up. Therefore, P1-EIA seems to be a valuable test for distinguishing between present and past E. histolytica infections.