Bovine spongiform encephalopathy: the effect of oral exposure dose on attack rate and incubation period in cattle

Author:

Wells G. A. H.1,Konold T.1,Arnold M. E.1,Austin A. R.1,Hawkins S. A. C.1,Stack M.1,Simmons M. M.1,Lee Y. H.2,Gavier-Widén D.3,Dawson M.1,Wilesmith J. W.1

Affiliation:

1. Veterinary Laboratories Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK

2. National Veterinary Research and Quarantine Service, Anyang, Republic of Korea

3. National Veterinary Institute (SVA), SE-75189 Uppsala, Sweden

Abstract

The dose–response of cattle exposed to the bovine spongiform encephalopathy (BSE) agent is an important component of modelling exposure risks for animals and humans and thereby, the modulation of surveillance and control strategies for BSE. In two experiments calves were dosed orally with a range of amounts of a pool of brainstems from BSE-affected cattle. Infectivity in the pool was determined by end-point titration in mice. Recipient cattle were monitored for clinical disease and, from the incidence of pathologically confirmed cases and their incubation periods (IPs), the attack rate and IP distribution according to dose were estimated. The dose at which 50 % of cattle would be clinically affected was estimated at 0.20 g brain material used in the experiment, with 95 % confidence intervals of 0.04–1.00 g. The IP was highly variable across all dose groups and followed a log-normal distribution, with decreasing mean as dose increased. There was no evidence of a threshold dose at which the probability of infection became vanishingly small, with 1/15 (7 %) of animals affected at the lowest dose (1 mg).

Publisher

Microbiology Society

Subject

Virology

Reference51 articles.

1. The age-dependent risk of infection to BSE of dairy cattle in Great Britain;Arnold;Prev Vet Med,2004

2. New observations on the clinical signs of BSE and scrapie;Austin,1994

3. Pathological temperament changes in bovine animals;Austin;Bovine Pract,1997

4. Bovine spongiform encephalopathy: diagnostic approach and clinical findings;Braun;Compend Contin Educ Pract Vet,1998

5. Transmission of bovine spongiform encephalopathy and scrapie to mice: strain variation and the species barrier;Bruce;Philos Trans R Soc Lond B Biol Sci,1994

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