Comparison of the immunoperoxidase monolayer assay and three commercial ELISAs for detection of antibodies against porcine circovirus type 2

The aim of this study was to compare and correlate antibody titres against porcine circovirus type 2 (PCV2) in porcine sera (n = 1270) obtained by immunoperoxidase monolayer assay (IPMA) with the results of three commercial ELISAs (designated E1, E2 and E3). The correlation between IPMA and ELISA results was excellent (r2 ≥ 0.90). Compared to IPMA, E2 had the highest sensitivity (93.0%), followed by E3 (90.1%) and E1 (85.0%); the specificity was 100% for all tests. All three commercial ELISAs had predictive values similar to those of IPMA and could be used to monitor antibody responses against PCV2 infection and/or vaccination.