Format

Send to

Choose Destination
Front Vet Sci. 2015 Sep 14;2:32. doi: 10.3389/fvets.2015.00032. eCollection 2015.

Objects in Contact with Classical Scrapie Sheep Act as a Reservoir for Scrapie Transmission.

Author information

1
Animal Sciences Unit, Animal and Plant Health Agency Weybridge , Addlestone , UK.
2
Pathology Department, Animal and Plant Health Agency Weybridge , Addlestone , UK.
3
Surveillance and Laboratory Services, Animal and Plant Health Agency Penrith , Penrith , UK.
4
ADAS UK, School of Veterinary Medicine and Science, University of Nottingham , Sutton Bonington , UK.
5
School of Veterinary Medicine and Science, University of Nottingham , Sutton Bonington , UK.

Abstract

Classical scrapie is an environmentally transmissible prion disease of sheep and goats. Prions can persist and remain potentially infectious in the environment for many years and thus pose a risk of infecting animals after re-stocking. In vitro studies using serial protein misfolding cyclic amplification (sPMCA) have suggested that objects on a scrapie-affected sheep farm could contribute to disease transmission. This in vivo study aimed to determine the role of field furniture (water troughs, feeding troughs, fencing, and other objects that sheep may rub against) used by a scrapie-infected sheep flock as a vector for disease transmission to scrapie-free lambs with the prion protein genotype VRQ/VRQ, which is associated with high susceptibility to classical scrapie. When the field furniture was placed in clean accommodation, sheep became infected when exposed to either a water trough (four out of five) or to objects used for rubbing (four out of seven). This field furniture had been used by the scrapie-infected flock 8 weeks earlier and had previously been shown to harbor scrapie prions by sPMCA. Sheep also became infected (20 out of 23) through exposure to contaminated field furniture placed within pasture not used by scrapie-infected sheep for 40 months, even though swabs from this furniture tested negative by PMCA. This infection rate decreased (1 out of 12) on the same paddock after replacement with clean field furniture. Twelve grazing sheep exposed to field furniture not in contact with scrapie-infected sheep for 18 months remained scrapie free. The findings of this study highlight the role of field furniture used by scrapie-infected sheep to act as a reservoir for disease re-introduction although infectivity declines considerably if the field furniture has not been in contact with scrapie-infected sheep for several months. PMCA may not be as sensitive as VRQ/VRQ sheep to test for environmental contamination.

KEYWORDS:

classical scrapie; field furniture; prion; reservoir; serial protein misfolding cyclic amplification; sheep; transmissible spongiform encephalopathy

Supplemental Content

Full text links

Icon for Frontiers Media SA Icon for PubMed Central
Loading ...
Support Center