EVALUATION OF DIAGNOSTIC-TESTS FOR HUMAN LEPTOSPIROSIS

The IgM-PK-ELISA, an enzyme-linked immunosorbent assay for immunoglobu lin M employing a proteinase K-treated antigen, and the ''Leptoteste-S '' macroagglutination test were evaluated for use in a rapid serodiagn osis of human leptospirosis. The microscopic agglutination test (MAT) was used as reference. The three serological tests were applied to ser um samples from patients with leptospirosis (N = 89), typhoid fever (N = 8), malaria (N = 19), syphilis (N = 20), hepatitis (N = 16) and fro m clinically healthy donors (N = 92), The overall results of the IgM-P K-ELISA and the ''Leptoteste-S'' are comparable to those of the MAT. H owever, both tests differed statistically from MAT in terms of the pos itivity of the acute-phase sera, with approximately 38% of the patient s with leptospirosis being identified earlier than when MAT was used, The IgM-PK-ELISA, with 89.9% sensitivity and 97.4% specificity, could be the test of choice for those laboratories which are equipped to per form ELISA. The ''Leptoteste-S'', with 89.9% sensitivity and 94.8% spe cificity, seems to be easier to perform and the most accessible to per ipheral laboratories for rapid screening of human sera. Both technique s present the important characteristic of detecting early antibodies a gainst leptospires, thus providing a diagnosis during the early stages of the disease.