Bovine spongiform encephalopathy (BSE) is a food-borne infection of cattle caused by the use of contaminated meat and bone meal in concentrated feeds. The UK epidemic was initiated by a sudden exposure to infection in 1981-1982, which was associated with a dramatic reduction in the use of organic solvents in the manufacture of meat and bone meal. This change almost certainly removed two partial disinfection steps and allowed enough contamination with a scrapie-like agent to infect cattle. Although it is assumed that the epidemic originated with scrapie infection crossing the species barrier, cattle-to-cattle recycling of infection, via feed, amplified the epidemic very considerably. There would have been a strong tendency for recycling to select a single cattle-adapted strain of agent, and this strain of BSE could well be different from scrapie. There is evidence to support both predictions. Because the median incubation period of BSE is 4-6 years, clinical cases did not appear until 1985-1986, by which time the recycling of infection in cattle was probably well established. However, the average food-borne exposure to infection has remained low resulting in a mainly sporadic occurrence of BSE. Signs of an imminent decline in the epidemic were unmistakable early in 1993, which is over 4 years after the feeding of ruminant-derived protein was banned to prevent new infections of cattle.

Keywords:
Bovine spongiform encephalopathy, Epidemiology, Food-borne infection, Species barriers, Selection of agent strains
This content is only available via PDF.
© 1993 S. Karger AG, Basel
1993
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.