Scrapie in sheep is a group of TSE strains non-transmissable to humans, and this disease has been widespread in Europe for several centuries. It is known that sheep can be experimentally infected with BSE, and that such BSE is similar to scrapie in terms of pathogenesis and clinical signs. Can BSE be transmitted under natural conditionsto livestock species other than cattle, and especially to sheep?
This project aism to:
Evaluate the BSE (and other TSE strains) transmission risk to sheep, and between infected and healthy sheep.
Evaluate the risk level for human health of an ovine adapted BSE strain
Estimate the current scientific ability to distinguish BSE from natural scrapie in sheep
Evaluate the currently available and future tools to detect BSE in sheep.
The project's objectives are to:
1. Evaluate the possibility of natural BSE dissemination in sheep herds in case of accidental contamination.
2. Determine the minimal oral infectious dose for BSE in sheep.
3. Characterize consequences of multi passage in sheep on BSE strain phenotype.
4. Evaluate strain detection in sheep in case of scrapie/BSE experimental co-infection.
5. Evaluate the effect of serial trans-species transmission on the species barrier, and more particularly on the human species barrier using transgenic mice models.
6. Confirm that the homozygous and heterozygote healthy A136R154R171 are not TSE 'silent carriers' and better understand the cellular basis of this resistance.
BSE horizontal transmission was observed in adult ewes (more than a year old) housed in a contaminated environment, which signify that BSE persistence risk, through inter-individual transmission, in accidentally contaminated sheep flocks is not zero. Comparisons between BSE affected sheep and scrapie affected sheep indicated that clinical signature and PrPsc distribution profile in brain are apparently not able to discriminate BSE in sheep from classical scrapie. Due to animal health problems (OHV-2 contamination) WP4 time schedule was deeply modified. New experiments in sheep will be conduct in year 3 (2005) of the project. That delay will obviously modify the initial work-plan and could possibly have consequences on completion of all tasks of this work package within the contract duration. Production of human transgenic mice was completed and experiments concerning 'human risk' took place in 2005.
ANIMALS, HUMAN HEALTH AND WELLBEING
Scientist responsible for the project
Dr OLIVIER ANDREOLETTI
Ecole Natioal Vétérinaire de Toulouse 23 Chemin des Capelles
31076 TOULOUSE CEDEX 03
France - FR
Phone: +33 5 61 19 39 69
Fax: +33 5 61 19 38 34
||Institut National de la Recherche Agronomique
||01 January 2003
||4 068 818 €
|Total EC contribution
||2 656 847 €
- VLA Weybridge, United Kingdom - UK
- CIDC Lelystad, Netherlands (The) - NL
- IAH Edinburgh, United Kingdom - UK
- University College Dublin, Ireland - IE