Development of Dot-ELISA for Diagnosis of Leptospirosis

Abstract

Dot-ELISA method for detection of leptospiral antibody was developed for screening in field trial during February-May, 2005. The optimized conditions were consisting of using pools of Leptospira interrogans serovar bratislavar and autumnalis antigens 1.75 µg/ml, 5% BSA for blocking, 1:80 serum dilution, a 1:1,500 goat anti-human IgG peroxidase conjugate, washed three times with PBS-tween in each washing step and incubated at room temperature. In all, 58 serum samples tested by MAT were used for this comparative study as the gold standard method. The sensitivity of specificity 63.4 percent, positive predictive value of 37.5 percent, negative predictive value of 76.5 percent and accuracy of 52.9 percent and 60.3 percent were reported. Cross reactions with syphilis, avian flu and scrub typhus were not found. This method would have a diagnostic potential under certain conditions. However more samples are needed in further evaluation of this test method.