Comparison of enzyme-linked immunosorbent assay and haemagglutination inhibition test for the detection of Newcastle disease virus antibodies in human sera.

A comparison of haemagglutination inhibition (HI) and enzyme-linked immunosorbent assay (ELISA) techniques for the detection of antibodies against Newcastle disease virus in sera from persons working in poultry farms and veterinary vaccine institutes and from the general population revealed that 22% more sera were positive by ELISA compared to HI. No samples were negative by ELISA but positive by HI. While HI titres of positive sera were found in the range 8-64, ELISA titres were between 16 and 512. It was interesting that though 78% sera had concordant results by the two tests, titres obtained by ELISA were nearly six times higher than those by HI.