Serodiagnosis of Indian kala-azar: evaluation of IFA, ELISA and CIEP tests.

Abstract

The sensitivity and specificity of three serological tests viz. indirect immunofluorescent antibody test (IFAT), enzyme linked immunosorbent assay (ELISA) and counterimmunoelectrophoresis (CIEP) for the diagnosis of Indian kala-azar were evaluated. Of the 209 patients in whom Leishmania donovani parasite could be demonstrated in bone marrow, 207 (99.04 per cent) could be diagnosed with IFAT, 203 (96.6 per cent) with CIEP and 208 (99.5 per cent) with ELISA. None of these serological tests was positive in 40 healthy individuals and 10 patients each with tuberculosis, toxoplasmosis and malaria. In only one out of 10 patients with malaria ELISA alone gave false positive result. Of the 119 patients who had clinical features simulating kala-azar but were negative for Leishmania donovani in bone marrow and responded to treatment other than that for Indian Kala-azar, IFAT, CIEP and ELISA were false positive in three (2.5 per cent), nil and three (2.5 per cent) cases, respectively. The use of serodiagnostic tests like ELISA for mass screening and CIEP in less well equipped peripheral laboratories is suggested.