Enhancing the Sensitivity of ELISA using Monoclonal and Polyclonal antibody to rWbSXP-1 Antigen

Earlier, we developed an ELISA based method for the detection of circulating filarial antigen using monoclonal (1F6H3) and polyclonal antibody to WbSXP-1 antigen (method I). Here, an attempt was made to enhance the sensitivity of this method with different reagent combinations which detected antigen up to 0.24ng/ml by method II, as against the 125ng/ml by method I. This also increased the optical density values in microfilaremic clinical samples up to 2.034 +/- 0.106 by method II against 0.792 +/- 0.055 by method I. There was 10% increase in number of samples showing antigen positive for Endemic Normal and Chronic Pathology by method II. The field application of Method II was evaluated using 4700 blood samples collected on microscopic slides. A total of 171 (3.64%) were found to have antigenemia, of which 168 samples were reported as endemic normal probably having occult filarial infection (MF-ve) and three were microfilaraemic positive by conventional staining method.