title: Strategic use of serology for the diagnosis of bovine tuberculosis after intradermal skin testing.
abstract: Diagnostic tests based on cell-mediated immunity are used in programmes for eradication of bovine tuberculosis (Mycobacterium bovis). Serological assays could be applied as ancillary methods to detect infected animals. Our objective was to evaluate two serological techniques: M. bovis Ab Test (IDEXX, USA) and Enferplex™ TB assay (Enfer, Ireland) in animals tested simultaneously with the single and comparative intradermal tests and the interferon-gamma assay. This work was performed at two stages. First, a preliminary panel of samples collected prior to intradermal tests from tuberculosis-free (n=60) and M. bovis-infected herds (n=78) was assayed, obtaining high specificity: 100% (M. bovis Ab Test) and 98.3% (Enferplex TB assay) but low sensitivity (detection of M. bovis infected animals): 23.9% (M. bovis Ab Test) and 32.6% (Enferplex TB assay). Subsequently, the use of serological techniques was further studied in two herds with M. bovis infection (n=77) using samples collected prior to, and 72 h and 15 days after PPD inoculation. The highest level of detection of infected animals for serology was achieved at 15 days post-intradermal tests taking advantage of the anamnestic effect: 70.4% and 85.2% in herd A, and 66.7% and 83.3% in herd B, using M. bovis Ab Test and Enferplex TB assay, respectively. Quantitative results (average values obtained with M. bovis Ab Test ELISA and degree of positivity obtained with Enferplex TB assay) were higher in animals showing lesions compatible with tuberculosis. No significant differences were observed in the number of confirmed infected animals detected with either serological technique.
authors.affiliation: Centro VISAVET, Universidad Complutense de Madrid, Av. Puerta de Hierro s/n, 28040 Madrid, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Casal
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Av. Puerta de Hierro s/n, 28040 Madrid, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Díez-Guerrier
authors.affiliation: Centro VISAVET, Universidad Complutense de Madrid, Av. Puerta de Hierro s/n, 28040 Madrid, Spain; Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Ctra. Colmenar Viejo, Km. 9100, 28034 Madrid, Spain.
authors.forename: Julio
authors.initials: J
authors.lastname: Álvarez
authors.affiliation: Centro VISAVET, Universidad Complutense de Madrid, Av. Puerta de Hierro s/n, 28040 Madrid, Spain; Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Av. Puerta de Hierro s/n, 28040 Madrid, Spain.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Rodriguez-Campos
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Av. Puerta de Hierro s/n, 28040 Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Mateos
authors.affiliation: IDEXX Livestock and Poultry Diagnostics, 1 Idexx Dr., Westbrook, ME 04092, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Linscott
authors.affiliation: IDEXX Livestock and Poultry Diagnostics, 1 Idexx Dr., Westbrook, ME 04092, USA.
authors.forename: Edmond
authors.initials: E
authors.lastname: Martel
authors.affiliation: IDEXX Livestock and Poultry Diagnostics, 1 Idexx Dr., Westbrook, ME 04092, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Lawrence
authors.affiliation: Enfer Scientific, Unit T, M7 Business Park, Newhall, Naas, Kildare, Ireland.
authors.forename: Clare
authors.initials: C
authors.lastname: Whelan
authors.affiliation: Enfer Scientific, Unit T, M7 Business Park, Newhall, Naas, Kildare, Ireland.
authors.forename: John
authors.initials: J
authors.lastname: Clarke
authors.affiliation: Enfer Scientific, Unit T, M7 Business Park, Newhall, Naas, Kildare, Ireland.
authors.forename: Amanda
authors.initials: A
authors.lastname: O'Brien
authors.affiliation: Centro VISAVET, Universidad Complutense de Madrid, Av. Puerta de Hierro s/n, 28040 Madrid, Spain; Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Av. Puerta de Hierro s/n, 28040 Madrid, Spain.
authors.forename: Lucas
authors.initials: L
authors.lastname: Domínguez
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Av. Puerta de Hierro s/n, 28040 Madrid, Spain. Electronic address: alaranaz@ucm.es.
authors.forename: Alicia
authors.initials: A
authors.lastname: Aranaz
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D002417:Cattle; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D007371:Interferon-gamma; D007428:Intradermal Tests / Q000662:veterinary; D009163:Mycobacterium bovis / Q000276:immunology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014374:Tuberculin Test / Q000592:standards / Q000662:veterinary*; D014380:Tuberculosis, Bovine / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology
chemical_list: D000907:Antibodies, Bacterial; D007371:Interferon-gamma
keywords: Boosting effect; Bovine tuberculosis; Diagnostic tests; Serological response