title: Evaluation of three rapid diagnostic tests used in bovine spongiform encephalopathy monitoring in Italy.
abstract: In 2001, a compulsory active surveillance system was started in the European Union to assess the prevalence of bovine spongiform encephalopathy (BSE) in the cattle population. The aim of the current study was to report on the field performances of 3 rapid tests: a Western blot (WB), a chemiluminescence enzyme-linked immunosorbent assay (ELISA), and an immunochromatographic assay, routinely used at 3 laboratories of the Istituto Zooprofilattico Sperimentale of Lombardia and Emilia Romagna, over 8 years of BSE monitoring activity. A total of 2,802,866 samples from slaughtered animals and 202,453 samples from fallen stock were tested by 1 of 3 tests. Positive results of the rapid tests were confirmed by histopathological examination, immunohistochemistry, and confirmatory WB. The field performances (i.e., initial reactive and false-positive rates) and practical aspects regarding resources and applicability of the tests to high-throughput routine testing laboratories were evaluated. The 3 tests proved to be reliable tools when applied to slaughtered samples, showing no or very low false-positive rates (<1 per 100,000 negative samples tested) and low retesting frequencies (0.02-0.26%). When samples from fallen stock were analyzed, performances of the immunochromatographic assay, and especially the chemiluminescence ELISA, were negatively affected, resulting in higher false-positive and retesting rates. On the other hand, both tests are less expensive, much easier to use, provide more rapid results, and adapt well to application in routine laboratories as compared with WB. In the authors' experience, the immunochromatographic assay was a good compromise between performance and convenience.
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna-Sezione Diagnostica di Modena, Modena, Italy. elena.carra@izsler.it
authors.forename: Elena
authors.initials: E
authors.lastname: Carra
authors.forename: Roberta
authors.initials: R
authors.lastname: Taddei
authors.forename: Ilaria
authors.initials: I
authors.lastname: Barbieri
authors.forename: Giuliana
authors.initials: G
authors.lastname: Botti
authors.forename: Vito
authors.initials: V
authors.lastname: Tranquillo
authors.forename: Alessandra
authors.initials: A
authors.lastname: Iori
authors.forename: Lucia
authors.initials: L
authors.lastname: Gibelli
authors.forename: Monica
authors.initials: M
authors.lastname: Cerioli
authors.forename: Patrizia
authors.initials: P
authors.lastname: Cavadini
authors.forename: Daniela
authors.initials: D
authors.lastname: Gelmetti
authors.forename: Stefano
authors.initials: S
authors.lastname: Pongolini
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Capucci
mesh_terms: D000003:Abattoirs / Q000592:standards; D000818:Animals; D000911:Antibodies, Monoclonal / Q000097:blood; D015153:Blotting, Western; D002417:Cattle; D016643:Encephalopathy, Bovine Spongiform / Q000175:diagnosis* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D007558:Italy; D049449:Luminescence; D008991:Monitoring, Physiologic / Q000379:methods / Q000662:veterinary
chemical_list: D000911:Antibodies, Monoclonal