NR AWLU
AU Penders,J.; Berkvens,D.; Praet,N.; Dispas,M.; Verbraeken,S.; Roels,S.; Thiry,E.; Saegerman,C.
TI Bayesian estimation of the true prevalence of BSE in Belgian cattle
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Poster sessions EPI-22
PT Konferenz-Poster
AB In 2002 and 2003, the mean apparent prevalence of BSE in Belgium was of 6.29 10-5. Since 2001, the detection system of this zoonosis has been based mainly on the use of a "rapid" test. The only rapid test in use in Belgium at that time was the Platelia(R) test, commercialized by Bio-Rad. At the development of the test, its sensitivity and specificity were estimated at 100% [95% CI: 99 - 100%] and 100% [95% CI: 99.7% - 100%] as the ability to accurately identify a non-infected animal. However, this test has generally been used in order to screen non-clinical populations. Under these conditions, the sensibility and specificity of the test could differ from the initially calculated values, and the true prevalence of BSE could diverge from the apparent prevalence. The sensibility and specificity of the rapid test, as well as the true prevalence of BSE in Belgium, have thus been estimated by Bayesian methods for the years 2002 and 2003. Prior distributions were obtained from expert opinion, and likelihood was based on data from tested animals. The posterior distribution of the true BSE prevalence used Markov Chain Monte Carlo Gibbs sampling. In 2002 and 2003, the true BSE prevalence in Belgium is situated in a credibility interval (CI) going from approximately 10 (exp-7) to 10 (exp-5). The specificity and sensitivity of the rapid test were estimated at 99.99% [CI: 99.99 - 100%] and 91.23% [CI: 81.69 - 91.64%] respectively. This study shows the importance of a critical study of the sensitivity and specificity of BSE diagnostic tests, as well as the apparent prevalence of this zoonosis, as their discrepancy with initial values could have important consequences for active and passive epidemiosurveillance of BSE.
AD J. Penders, C. Saegerman: Epidemiology and Risk analysis applied to Veterinary sciences, Department of Infectious and Parasitics diseases, University of Liège, B-4000 Liège, Belgium; D. Berkvens, N. Praet: Department of Tropical Animal Health and Production, Institute of Tropical Medicine, B-2000 Antwerp, Belgium; M. Dispas, S. Roels: Veterinary and Agrochemical Research Center, B-1180 Uccle, Belgium; S. Verbraeken: Federal Agency for the Safety of the Food Chain, B-1000 Brussels, Belgium; E.Thiry: not stated. E-mail: claude.saegerman@ulg.ac.be
SP englisch
PO Italien