Comparative epidemiology of scrapie outbreaks in individual sheep focks

Authors

C. A. Redman, UniŠersity of Edinburgh
P. G. Coen, UniŠersity of Edinburgh
R. M. Lewis, Scottish Agricultural CollegeFollow
W. S. Dingwall, Scottish Agricultural College
J. D. Foster, Institute for Animal Health Neuropathogenesis Unit
M. E. Chase-Topping, UniŠersity of Edinburgh
N. Hunter, Institute for Animal Health Neuropathogenesis Unit
M. Woolhouse, UniŠersity of Edinburgh
L. Matthews, UniŠersity of Edinburgh

Date of this Version

2002

Citation

Epidemiol. Infect. (2002), 128, 513±521. DOI: 10.1017/S0950268802007008

Comments

Copyright 2002, Cambridge University Press. Used by permission.

Abstract

Data recording the course of scrapie outbreaks in 4 sheep flocks (2 in Cheviot sheep and 2 in Suffolks) are compared. For each outbreak the data on scrapie incidence and sheep demography and pedigrees cover periods of years or decades. A key finding is that the incidence of clinical cases peaks in sheep 2-3 years old, despite very different forces-of infection.This is consistent with age-specific susceptibility of sheep to scrapie, as has beenreported for cattle to bovine spongiform encephalopathy and for humans to variant Creutzfeldt-Jakob disease. Scrapie incidence was higher in ewes than rams and at certain times of years, though these effects were not consistent between flocks. There was no evidence for high levels of vertical transmission.