Evaluation of newly developed immunoperoxidase monolayer assays for detection of antibodies against bovine herpesvirus 4

This study describes the evaluation of immunoperoxidase monolayer assays (I PMAs) for detection of antibodies against bovine herpesvirus 4 (BHV4) DN-59 9 or BHV4 LVR 140 in sera of cattle. We compared the quality of these IPMAs with the quality of a BHV4 indirect enzyme-linked immunosorbent assay (ELI SA). In addition, a preliminary serological survey of BHV4 antibodies was c arried out to estimate the seroprevalence of BHV4 in Dutch cattle at differ ent ages. The specificities of both BHV4 IPMAs were 1.00, The geometrical m ean titers (detection limit) of the BHV4 IPMAs were twice as high as that o f the BHV4 indirect ELISA. In experimentally infected cattle, BHV4 antibodi es were detectable by IPMAs 16 to 18 days postinfection, which was almost 2 weeks earlier than in the indirect ELISA, The reproducibility of the BHV4 DN-599 IPMA (D-kappa value, 0.92) and of the BHV4 LVR 140 IPMA (kappa D val ue, 0.87) were good. For field sera the overall agreement between the BHV4 indirect ELISA and the two BHV4 IPMAs, DN-599 and LVR 140, was 95 and 96%, respectively. The serological-survey study showed that the estimated seropr evalence of BHV4 in Dutch cattle was 16 to 18% and that the percentage of B HV4-positive animals varied by age category (between 6 and 43%), In summary , the two BHV4 IPMA formats have several advantages that make IPMA a useful alternative to the BHV4 indirect ELISA for detecting BHV4 antibodies in ca ttle.