title: Assessment of performance of selected serological tests for diagnosing brucellosis in pigs.
abstract: Swine brucellosis due to Brucella suis is considered an emerging zoonotic disease whose control is based on serological testing and the subsequent culling of seropositive animals or the full depopulation of affected flocks. Here we assessed the performance of several serological tests (Rose Bengal Test [RBT], indirect ELISA [i-ELISA], blocking ELISA [b-ELISA], and two competitive ELISAs [c-ELISA]) for diagnosing swine brucellosis caused by B. suis biovar 2. Both frequentistic and Bayesian statistical inference were used. A frequentistic analysis, using sera from known gold standard (GS) populations (i.e., from truly infected or brucellosis free animals), resulted in maximum (100%) diagnostic sensitivity (Se) and specificity (Sp) in the RBT, i-ELISA and b-ELISA tests. However, c-ELISAs resulted in lower diagnostic Se (ranging from 68.5% to 92.6%, according to the different cut-offs selected). A Bayesian analysis of tests yielding the best diagnostic performance with GS sera (RBT, i-ELISA and b-ELISA), but using a large collection of field sera, resulted in similar Se among tests but markedly lower (≈ 80%) than that resulting from the frequentistic analysis using the GS serum populations. By contrast, the estimated Sp in the Bayesian analysis was only slightly lower than 100%, thus similar to that obtained frequentistically. Our results show that adequate diagnostic tests for brucellosis in swine are available, but also emphasize the need for more extensive validation studies before applying these tests under field conditions.
authors.affiliation: Unidad de Sanidad Animal, Centro de Investigación y Tecnología Agroalimentaria (CITA), del Gobierno de Aragón, Av. Montañana 930, 50059 Zaragoza, Spain.
authors.forename: Pilar M
authors.initials: PM
authors.lastname: Muñoz
authors.forename: José M
authors.initials: JM
authors.lastname: Blasco
authors.forename: Bas
authors.initials: B
authors.lastname: Engel
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: de Miguel
authors.forename: Clara M
authors.initials: CM
authors.lastname: Marín
authors.forename: Lucía
authors.initials: L
authors.lastname: Dieste
authors.forename: Raúl C
authors.initials: RC
authors.lastname: Mainar-Jaime
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D041021:Brucella suis / Q000302:isolation & purification*; D002006:Brucellosis / Q000097:blood / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000592:standards / Q000662:veterinary*; D005260:Female; D012395:Rose Bengal / Q000737:chemistry; D012680:Sensitivity and Specificity; D013552:Swine; D013553:Swine Diseases / Q000097:blood / Q000175:diagnosis / Q000382:microbiology*; D015047:Zoonoses / Q000382:microbiology*
chemical_list: D012395:Rose Bengal