Validation and evaluation of a commercially available ELISA for the detection of antibodies specific to bovine viral diarrhoea virus (bovine pestivirus)

Abstract

To compare the performance of an enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies specific to bovine viral diarrhoea virus (BVDV) with a virus neutralisation test (VNT) and agarose gel immunodiffusion (AGID) test. A total of 125 cattle serum samples were tested by a commercially available ELISA for antibodies specific to BVDV and by a VNT as the reference standard. A comparison between AGID and ELISA for detection of BVDV antibodies was also carried out, using 1182 serum samples from unvaccinated South Australian cattle. Two-graph receiver operating characteristics (TG-ROC) analysis was used to confirm that the manufacturer's recommended cut-off value for the ELISA was appropriate. Two-by-two tables were constructed to analyse the concordance of serological results among the three assays. McNemar tests were used to assess the agreement among serological tests. Using the manufacturer's cut-off threshold, supported by TG-ROC analysis, the ELISA's sensitivity and specificity were calculated to be 96.7% and 97.1%, respectively, compared with the VNT. Compared with AGID, ELISA with specific BVDV antibodies may be more sensitive and detect 5.8% more samples than AGID. McNemar test also showed a significant difference (P < 0.001) between AGID and ELISA.