Development and validation of a recombinant capsid protein-based ELISA for detection of antibody to porcine circovirus type 2

Porcine circovirus type 2 (PCV2) has been recently associated with a number of disease syndromes, especially postweaning multisystemic wasting disease (PMWS). Herein, an alternative indirect enzyme-linked immunosorbent assay (ELISA) for detection of PCV2 antibody was developed using nuclear localization signal-truncated capsid protein of PCV2 produced in Escherichia coli (CAP ELISA). This assay was validated by comparison with an indirect immunofluorescence assay (IIF) and a PCV2-based ELISA. The diagnostic sensitivity (DSN), specificity (DSP) and accuracy of the CAP ELISA were 95.3%, 93.9% and 95.1%, compared with IIF on 1080 field serum samples, and 93.3%, 84.2% and 91.1%, compared with the PCV2-based ELISA on 79 field sera, respectively. Cross-reactivity assay showed that this assay was PCV2-specific. Repeatability tests revealed that the coefficients of variation of positive sera within and between runs were less than 15%. This ELISA is simpler to produce and perform, time-saving and suitable for large scale surveys of PCV2 infection at low cost and the evaluation of the efficiency of various vaccines against PCV2. (C) 2007 Elsevier Ltd. All rights reserved.