NR AXKU
AU de Vos,C.J.; Heres,L.
TI Quantitative Assessment of the BSE Risk from Processing Meat and Bone Meal in Feed for Non-Ruminants in the Netherlands
QU International Conference - Prion 2007 (26.-28.9.2007) Edinburgh International Conference Centre, Edinburgh, Scotland, UK - Book of Abstracts: Epidemiology, Risk Assessment and Transmission P04.59
IA http://www.prion2007.com/pdf/Prion Book of Abstracts.pdf
PT Konferenz-Poster
AB
Background: Meat and bone meal (MBM) derived from infected cattle is the major infection route for BSE. The total ban on use of MBM in livestock feed has been very successful in reducing BSE spread, but also implies a waste of high quality proteins resulting in economic and ecological loss. The BSE epidemic in the Netherlands is now on its return and a partial lifting of the total ban on MBM might be considered.
Aim: The aim of this study was to assess the BSE risk for the Netherlands if MBM derived from animals fit for human consumption, i.e. category 3 MBM, would be used exclusively in non-ruminant feed.
Methods: A stochastic simulation model was constructed that calculates (i) the probability that infectious material of non-detected BSE-infected cows ends up with calves and (ii) the amount of infectious material (AIM) consumed by calves in case of such an incident. Three pathways were considered via which the infectious material can reach calves: (a) cross-contamination in the feed mill if both ruminant and nonruminant feed are prepared at the same location, (b) cross-contamination on the primary farm if both dairy cattle and non-ruminants are present, and (c) contamination of grassland if manure of non-ruminants is applied as fertiliser.
Results: Model calculations indicate that the overall probability that infectious material of a non-detected BSE-infected cow ends up with calves is 3.2%. In most incidents the AIM is extremely small (median = 5.9x10-12 ID50; mean = 1.9x10-4 ID50). Based on
the average AIM per incident cross-contamination in the feed mill is the most risky pathway. Simultaneous relaxation of other BSE control measures, including testing only a sample of cattle in the active surveillance, increases the average AIM per incident to 5.0x10-3 ID50. Serious mistakes in processing MBM can result in even higher
doses of infectious material ending up with calves if category 1 MBM would be processed.
Discussion and conclusion: To assess the overall risk of new BSE infections model results should be combined with BSE prevalence estimates. For the Netherlands only a few BSE cases are expected in the coming years. We therefore conclude that the BSE risk of using category 3 MBM derived from Dutch cattle in feed for non-ruminants is very low.
AD C. de Vos, L. Heres, Central Institute for Animal Disease Control (CIDC-Lelystad), Netherlands
SP englisch
PO Schottland