HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Wells, G. A. H. Articles by Wilesmith, J. W. Search for Related Content PubMed PubMed Citation Articles by Wells, G. A. H. Articles by Wilesmith, J. W. Agricola Articles by Wells, G. A. H. Articles by Wilesmith, J. W.

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

A. R. Austin^1,

M. Dawson^1,

J. W. Wilesmith^1,

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

Correspondence
G. A. H. Wells
g.a.h.wells{at}vla.defra.gsi.gov.uk

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).

Present address: Oak Farm, Harpsden Bottom, Henley-on-Thames, Oxon RG9 4HY, UK.

Present address: NSPAC, Defra, Whittington Road, Worcester WR5 2SU, UK.

Present address: Defra, 1a Page Street, London SWIP 4PQ, UK, and Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, University of London, Keppel Street, London WC1E 7HT, UK.

This article has been cited by other articles:

				P. J. Burke Preliminary epidemiological analysis of BSE cases born after 2000 in Great Britain Vet Rec., March 21, 2009; 164(12): 370 - 371. [Full Text] [PDF]

				H. J. Sohn, Y. H. Lee, R. B. Green, Y. I. Spencer, S. A. C. Hawkins, M. J. Stack, T. Konold, G. A. H. Wells, D. Matthews, I. S. Cho, et al. Bone marrow infectivity in cattle exposed to the bovine spongiform encephalopathy agent Vet Rec., February 28, 2009; 164(9): 272 - 273. [Full Text] [PDF]

				M. E. Arnold, J. B. M. Ryan, T. Konold, M. M. Simmons, Y. I. Spencer, A. Wear, M. Chaplin, M. Stack, S. Czub, R. Mueller, et al. Estimating the temporal relationship between PrPSc detection and incubation period in experimental bovine spongiform encephalopathy of cattle J. Gen. Virol., November 1, 2007; 88(11): 3198 - 3208. [Abstract] [Full Text] [PDF]

				K. Masujin, D. Matthews, G. A. H. Wells, S. Mohri, and T. Yokoyama Prions in the peripheral nerves of bovine spongiform encephalopathy-affected cattle J. Gen. Virol., June 1, 2007; 88(6): 1850 - 1858. [Abstract] [Full Text] [PDF]