McIntyre, K Marie; Gubbins, Simon; Goldmann, Wilfred; Stevenson, Emily and Baylis, Matthew (2006) The time-course of a scrapie outbreak. BMC Veterinary Research, 2 . Article Number: 20. ISSN 1746-6148
Available under License Creative Commons Attribution.
Background: Because the incubation period of scrapie has a strong host genetic component and a dose-response relationship, it is possible that changes will occur during an outbreak, especially in the genotypes of cases, age-at-onset of disease and, perhaps, the clinical signs displayed. We investigated these factors for a large outbreak of natural scrapie, which yielded sufficient data to detect temporal trends. Results: Cases occurred mostly in two genotypes, VRQ/VRQ and VRQ/ARQ, with those early in the outbreak more likely to be of the VRQ/VRQ genotype. As the epidemic progressed, the ageat- onset of disease increased, which reflected changes in the genotypes of cases rather than changes in the age-at-onset within genotypes. Clinical signs of cases changed over the course of the outbreak. As the epidemic progressed VRQ/VRQ and VRQ/ARQ sheep were more likely to be reported with behavioural changes, while VRQ/VRQ sheep only were less likely to be reported with loss of condition. Conclusion: This study of one of the largest scrapie outbreaks in the UK allowed investigation of the effect of PrP genotype on other epidemiological parameters. Our analysis indicated that, although age-at-onset and clinical signs changed over time, the observed changes were largely, but not exclusively, driven by the time course of the PrP genotypes of cases.
|Additional Information:||Published: 13 June 2006. 6 pages (page numbers not for citation purposes).|
|Uncontrolled Keywords:||PrP genotype; epidimiological parameters; genotypes; age-at-onset; clinical signs; behavioural changes|
|Subjects:||S Agriculture > SF Animal culture|
|Departments, Research Centres and Related Units:||Academic Faculties, Institutes and Research Centres > Faculty of Veterinary Science > Department of Veterinary Clinical Science|
|Publisher's Statement:||© 2006 McIntyre et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.|
|Deposited On:||01 Jul 2008 16:41|
|Last Modified:||18 Apr 2013 14:32|
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