title: Bayesian estimation of sensitivity and specificity of a commercial serum/milk ELISA against the Mycobacterium avium subsp. Paratuberculosis (MAP) antibody response for each lactation stage in Greek dairy sheep.
abstract: A total of 854 paired milk and blood samples were collected from ewes of a Greek flock and used to estimate the sensitivity and specificity of a commercial ELISA for detection of Mycobacterium avium subsp. paratuberculosis (MAP) specific antibodies in each stage of lactation. We implemented Bayesian mixture models to derive the distributions of the test response for the healthy and the infected ewes. In the colostrum period, early, mid and late lactation stage the median values of the area under the curves (AUC) were 0.61 (95% credible interval: 0.50; 0.84), 0.61 (0.51;0.84), 0.65 (0.51;0.91), 0.65(0.51;0.89) for the serum ELISA and and 0.60 (0.50; 0.84), 0.61 (0.50; 0.84), 0.67(0.51; 0.91), 0.66(0.50; 0.90) for the milk ELISA, respectively. Both serum and milk ELISA had low to average overall discriminatory ability as measured by the area under the curves and comparable sensitivities and specificities at the recommended cutoffs.
authors.affiliation: Laboratory of Epidemiology, Biostatistics and Animal Health Economics, Faculty of Veterinary Medicine, University of Thessaly, Trikalon 224, GR-43100 Karditsa, Greece. Electronic address: eaggel@vet.uth.gr.
authors.forename: Elisavet
authors.initials: E
authors.lastname: Angelidou
authors.affiliation: Laboratory of Epidemiology, Biostatistics and Animal Health Economics, Faculty of Veterinary Medicine, University of Thessaly, Trikalon 224, GR-43100 Karditsa, Greece.
authors.forename: Polychronis
authors.initials: P
authors.lastname: Kostoulas
authors.affiliation: Laboratory of Epidemiology, Biostatistics and Animal Health Economics, Faculty of Veterinary Medicine, University of Thessaly, Trikalon 224, GR-43100 Karditsa, Greece.
authors.forename: Leonidas
authors.initials: L
authors.lastname: Leontides
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis / Q000097:blood; D001499:Bayes Theorem; D003612:Dairying / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary*; D005260:Female; D006115:Greece / Q000453:epidemiology; D007774:Lactation; D008892:Milk / Q000382:microbiology*; D016927:Mycobacterium avium subsp. paratuberculosis / Q000302:isolation & purification*; D010283:Paratuberculosis / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D012680:Sensitivity and Specificity; D044967:Serum / Q000382:microbiology*; D012756:Sheep; D012757:Sheep Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology
chemical_list: D000907:Antibodies, Bacterial
keywords: Milk ELISA; Paratuberculosis; Sheep; Validation