title: A retrospective evaluation of a Bovine Herpesvirus-1 (BHV-1) antibody ELISA on bulk-tank milk samples for classification of the BHV-1 status of Danish dairy herds.
abstract: Bulk-tank milk samples analysed in a Bovine Herpesvirus-1 (BHV-1) blocking ELISA are still in use in the Danish BHV-1 programme as a tool to classify dairy herds as BHV-1 infected or BHV-1 free herds. In this retrospective study, we used data from the Danish BHV-1 eradication campaign to evaluate performance characteristics of the BHV-1 blocking ELISA in 1039 BHV-1-seropositive and 502 repeatedly BHV-1-negative dairy herds using the results of blood testing of the individual animals as the true infection status. At a cut-off value of 30% blocking reaction, the herd-level relative sensitivity and relative specificity were 82 and 100%, respectively. The herd-level relative sensitivity depended on the within-herd prevalence of seropositive cows and the cut-off value in the assay, but not on the time interval (up to 90 days) between the collection of the bulk-tank milk sample and the individual serum samples. The BHV-1 blocking ELISA on bulk-tank milk could detect seropositive herds (few), with prevalence proportions as low as one seropositive cow out of 70 cows.
authors.affiliation: Danish Dairy Board, Veterinary and Milk Quality Department, 22 Frederiks Allé, DK-8000 Aarhus, Denmark.
authors.forename: B
authors.initials: B
authors.lastname: Nylin
authors.forename: U
authors.initials: U
authors.lastname: Strøger
authors.forename: L
authors.initials: L
authors.lastname: Rønsholt
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000302:isolation & purification*; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000821:virology; D003612:Dairying; D003718:Denmark / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D006566:Herpesviridae Infections / Q000453:epidemiology / Q000662:veterinary*; D007242:Herpesvirus 1, Bovine / Q000276:immunology*; D008892:Milk / Q000276:immunology / Q000821:virology*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D000914:Antibodies, Viral