Article Text

Trends in age at detection in cases of bovine spongiform encephalopathy in Belgium: an indicator of the epidemic curve
  1. C. Saegerman, DVM, MSc, PhD, DipECVPH1,
  2. N. Speybroeck, BSc, MSc, PhD2,
  3. E. Vanopdenbosch, DVM, MSc3,
  4. J. W. Wilesmith, BVSc, HonMFPHM, DipECVPH, MRCVS4 and
  5. D. Berkvens, BSc, MSc, PhD2
  1. 1 Secretariat of the Scientific Committee, Administration of Control Policy, Federal Agency for the Safety of the Food Chain, World Trade Center III, Avenue Simon Bolivar 30, B-1000 Brussels, Belgium
  2. 2 Department of Tropical Animal Health and Production, Institute of Tropical Medicine, Nationalestraat 155, B-2000 Antwerp, Belgium
  3. 3 Veterinary and Agrochemical Research Center, Groeselenberg 99, B-1180 Uccle, Belgium
  4. 4 Department of Epidemiology, Veterinary Laboratories Agency, New Haw, Addlestone, Surrey KT15 3NB
  1. Dr Speybroeck's present address is World Health Organization, Evidence and Information for Policy, Avenue Apia 20, CH-1211 Geneva 27, Switzerland
  2. Professor Saegerman's present address is Department of Infectious and Parasitic Diseases, University of Liège, Boulevard de Colonster 20 B42, B-4000 Liège, Belgium


There were 118 cases of bovine spongiform encephalopathy (bse) in Belgium before January 1, 2004. Trends in their age at detection were analysed and attempts were made to use this parameter as a predictor of the current status of the bse epidemic in the country. The following variables were considered: date of birth, breed, date of detection, mode of detection, and the number and age of animals slaughtered and rendered each month. Age at detection as a function of date of birth was a very poor epidemiological indicator. It was concluded that the increasing age of bse cases when they were detected was due to the depletion of cases, as a result of there being no new infections, and that it is a reliable indicator of a decrease in the epidemic curve in Belgium. By means of a simulation it is shown how age distribution at the time of detection closely follows the epidemic curve and data from Great Britain are used to illustrate the point.

Statistics from

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.