Feed-borne transmission and case clustering of BSE

Citation
Tj. Hagenaars et al., Feed-borne transmission and case clustering of BSE, P ROY SOC B, 267(1440), 2000, pp. 205-215
Citations number
25
Categorie Soggetti
Experimental Biology
Journal title
PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES B-BIOLOGICAL SCIENCES
ISSN journal
09628452 → ACNP
Volume
267
Issue
1440
Year of publication
2000
Pages
205 - 215
Database
ISI
SICI code
0962-8452(20000207)267:1440<205:FTACCO>2.0.ZU;2-T
Abstract
An unresolved issue in the epidemiology of bovine spongiform encephalopathy (BSE) in the UK is what precisely determines the degree to which cases of disease in cattle are clustered within herds throughout the course of the e pidemic. This paper presents an analysis of feed-borne transmission at the herd level and tests various models of case-clustering mechanisms, associat ed with heterogeneity in exposure to infectious feed, against observed epid emic pattern. We use an age-structured metapopulation framework in which th e recycling of animal tissue between herds via feed producers is explicitly described. We explore two alternative assumptions for the scaling with her d size of the within-herd risk of exposure of an animal to infectious mater ial. We find that whereas exposure heterogeneity caused by variation in fee d and offal processing methods and by variation in per-animal feed uptake c an explain the pattern of case clustering seen in the BSE epidemic, exposur e heterogeneity due to the aggregation of infectivity within feed cannot.