title: Estimation of sensitivity and specificity of bacteriology, histopathology and PCR for the confirmatory diagnosis of bovine tuberculosis using latent class analysis.
abstract: Bacteriology and histopathology are the most commonly used tests used for official confirmatory diagnosis of bovine tuberculosis (bTB) in cattle in most countries. PCR is also being used increasingly because it allows a fast diagnosis. This test could be applied as a supplement to or replacement for current bTB confirmatory diagnostic tests but its characteristics have first to be evaluated. The aim of this study was to estimate and compare sensitivities and specificities of bacteriology, histopathology and PCR under French field conditions, in the absence of a gold standard using latent class analysis. The studied population consisted of 5,211 animals from which samples were subjected to bacteriology and PCR (LSI VetMAX™ Mycobacterium tuberculosis Complex PCR Kit, Life Technologies) as their herd of origin was either suspected or confirmed infected with bTB or because bTB-like lesions were detected during slaughterhouse inspection. Samples from 697 of these animals (all with bTB-like lesions) were subjected to histopathology. Bayesian models were developed, allowing for dependence between bacteriology and PCR, while assuming independence from histopathology. The sensitivity of PCR was higher than that of bacteriology (on average 87.7% [82.5-92.3%] versus 78.1% [72.9-82.8%]) while specificity of both tests was very good (on average 97.0% for PCR [94.3-99.0%] and 99.1% for bacteriology [97.1-100.0%]). Histopathology was at least as sensitive as PCR (on average 93.6% [89.9-96.9%]) but less specific than the two other tests (on average 83.3% [78.7-87.6%]). These results suggest that PCR has the potential to replace bacteriology to confirm bTB in samples submitted from suspect cattle.
authors.affiliation: Epidemiology Unit, Paris-Est University, Anses, Laboratory for Animal Health, Maisons-Alfort, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Courcoul
authors.affiliation: Regional Analysis and Research Laboratory of Dordogne (LDAR24), Coulounieix-Chamiers, France.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Moyen
authors.affiliation: Regional Analysis and Research Laboratory of Dordogne (LDAR24), Coulounieix-Chamiers, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Brugère
authors.affiliation: Regional Analysis and Research Laboratory of Dordogne (LDAR24), Coulounieix-Chamiers, France.
authors.forename: Sandy
authors.initials: S
authors.lastname: Faye
authors.affiliation: Bovine Tuberculosis Reference Laboratory, Paris-Est University, Anses, Laboratory for Animal Health, Bacterial Zoonoses Unit, Maisons-Alfort, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Hénault
authors.affiliation: Regional Analysis and Research Laboratory of Dordogne (LDAR24), Coulounieix-Chamiers, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Gares
authors.affiliation: Bovine Tuberculosis Reference Laboratory, Paris-Est University, Anses, Laboratory for Animal Health, Bacterial Zoonoses Unit, Maisons-Alfort, France.
authors.forename: Maria-Laura
authors.initials: ML
authors.lastname: Boschiroli
mesh_terms: D000003:Abattoirs; D000818:Animals; D001431:Bacteriological Techniques / Q000379:methods; D001499:Bayes Theorem; D002417:Cattle / Q000382:microbiology; D005260:Female; D005602:France; D005798:Genes, Bacterial; D008297:Male; D009163:Mycobacterium bovis; D016133:Polymerase Chain Reaction / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014380:Tuberculosis, Bovine / Q000175:diagnosis*