Previous Article | Next Article 
Journal of Clinical Microbiology, February 2005, p. 862-869, Vol. 43, No. 2
0095-1137/05/$08.00+0 doi:10.1128/JCM.43.2.862-869.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.
Population-Level Retrospective Study of Neurologically Expressed Disorders in Ruminants before the Onset of Bovine Spongiform Encephalopathy (BSE) in Belgium, a BSE Risk III Country
C. Saegerman,1 D. Berkvens,2 L. Claes,3 A. Dewaele,4 F. Coignoul,4 R. Ducatelle,5 D. Cassart,4 B. Brochier,6 F. Costy,7 S. Roels,8 H. Deluyker,9,
E. Vanopdenbosch,8 and
E. Thiry10*
Federal Agency for the Safety of the Food Chain, Administration of Control Policy, Secretariat of the Scientific Committee,1 Department of Microbiology, Section of Virology, Scientific Institute of Public Health,6 Institut Pasteur, Rabies Service,7 Veterinary and Agrochemical Research Center (CODA/CERVA), National Reference Laboratory for Veterinary TSE, Brussels,8 Prince Leopold Institute of Tropical Medicine, Department of Animal Health, Antwerp,2 Dierengezondheidszorg Vlaanderen, Leefdaal,3 Department of Pathology,4 Department of Infectious and Parasitic Diseases, Virology, Epidemiology, and Viral Diseases, Faculty of Veterinary Medicine, University of Liège, Liège,10 Vakgroep Pathologie, Bacteriologie en Pluimveeziekten,5 Vakgroep Verloskunde, Voortplantig en Bedrijfsdiergeneeskunde, Faculteit Diergeneeskunde, Universiteit Ghent, Merelbeke, Belgium9
Received 25 June 2004/ Returned for modification 12 September 2004/ Accepted 17 October 2004
A retrospective epidemiological study (n = 7,875) of neurologically expressed disorders (NED) in ruminants before the onset of the bovine spongiform encephalopathy epidemic (years studied, 1980 to 1997) was carried out in Belgium. The archives of all veterinary laboratories and rabies and transmissible spongiform encephalopathy (TSE) epidemiosurveillance networks were consulted. For all species, a significantly higher number of NED with virological causes (rabies) was reported south of the Sambre-Meuse Valley. During the period 1992 to 1997, for which the data were complete, (i) the predicted annual incidence of NED varied significantly as a function of species and area (higher numbers in areas where rabies was present) but was always above 100 cases per million, and (ii) the mean incidence of suspected TSE cases and, among them, those investigated by histopathological examination varied significantly as a function of species and area. The positive predictive value of a presumptive clinical diagnosis of NED ranged from 0.13 (game) to 0.63 (sheep). Knowledge of the positive predictive value permits the definition of a reference point before certain actions (e.g., awareness and training campaigns) are undertaken. It also shows the usefulness of a systematic necropsy or complementary laboratory tests to establish an etiological diagnosis. TSE analysis of a small, targeted historical sampling (n = 48) permitted the confirmation of one case and uncovered another case of scrapie. The results of the present study help to develop and maintain the quality of the worldwide clinical epidemiological networks for TSE, especially in countries that in the past imported live animals, animal products, and feedstuffs from countries with TSE cases.
* Corresponding author. Mailing address: Department of Infectious and Parasitic Diseases, Virology, Epidemiology, and Viral Diseases, Faculty of Veterinary Medicine, University of Liège, Boulevard de Colonster, 20, B43b, B-4000 Liège, Belgium. Phone: 32/4 366-42-50. Fax: 32/4 366-42-61. E-mail: etienne.thiry{at}ulg.ac.be.
Present address: European Food Safety Authority, B-1140 Brussels, Belgium.
Journal of Clinical Microbiology, February 2005, p. 862-869, Vol. 43, No. 2
0095-1137/05/$08.00+0 doi:10.1128/JCM.43.2.862-869.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»