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BioMed Research International
Volume 2015 (2015), Article ID 931542, 7 pages
Research Article

Bayesian Estimation of the True Prevalence and of the Diagnostic Test Sensitivity and Specificity of Enteropathogenic Yersinia in Finnish Pig Serum Samples

1Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, Agnes Sjöbergin katu 2, 00014 Helsinki, Finland
2Research and Laboratory Department, Risk Assessment Research Unit, EVIRA Finnish Food Safety Authority, Mustialankatu 3, 00790 Helsinki, Finland

Received 28 November 2014; Revised 1 April 2015; Accepted 13 April 2015

Academic Editor: Pablo Fernández-Escámez

Copyright © 2015 M. J. Vilar et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Bayesian analysis was used to estimate the pig’s and herd’s true prevalence of enteropathogenic Yersinia in serum samples collected from Finnish pig farms. The sensitivity and specificity of the diagnostic test were also estimated for the commercially available ELISA which is used for antibody detection against enteropathogenic Yersinia. The Bayesian analysis was performed in two steps; the first step estimated the prior true prevalence of enteropathogenic Yersinia with data obtained from a systematic review of the literature. In the second step, data of the apparent prevalence (cross-sectional study data), prior true prevalence (first step), and estimated sensitivity and specificity of the diagnostic methods were used for building the Bayesian model. The true prevalence of Yersinia in slaughter-age pigs was 67.5% (95% PI 63.2–70.9). The true prevalence of Yersinia in sows was 74.0% (95% PI 57.3–82.4). The estimates of sensitivity and specificity values of the ELISA were 79.5% and 96.9%.