title: Soil clay content underlies prion infection odds.
abstract: Environmental factors-especially soil properties-have been suggested as potentially important in the transmission of infectious prion diseases. Because binding to montmorillonite (an aluminosilicate clay mineral) or clay-enriched soils had been shown to enhance experimental prion transmissibility, we hypothesized that prion transmission among mule deer might also be enhanced in ranges with relatively high soil clay content. In this study, we report apparent influences of soil clay content on the odds of prion infection in free-ranging deer. Analysis of data from prion-infected deer herds in northern Colorado, USA, revealed that a 1% increase in the clay-sized particle content in soils within the approximate home range of an individual deer increased its odds of infection by up to 8.9%. Our findings suggest that soil clay content and related environmental properties deserve greater attention in assessing risks of prion disease outbreaks and prospects for their control in both natural and production settings.
authors.affiliation: United States Department of the Interior, United States Geological Survey, Colorado Cooperative Fish and Wildlife Research Unit, Fort Collins, Colorado 80523-1484, USA.
authors.forename: W
authors.initials: W
authors.lastname: David Walter
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Walsh
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Farnsworth
authors.forename: Dana L
authors.initials: DL
authors.lastname: Winkelman
authors.forename: Michael W
authors.initials: MW
authors.lastname: Miller
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D001546:Bentonite / Q000737:chemistry / Q000378:metabolism*; D016000:Cluster Analysis; D003120:Colorado; D003198:Computer Simulation; D003670:Deer; D016013:Likelihood Functions; D008962:Models, Theoretical; D017096:Prion Diseases / Q000635:transmission* / Q000662:veterinary*; D011328:Prions / Q000378:metabolism*; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012987:Soil / Q000032:analysis*
chemical_list: D011328:Prions; D012987:Soil; D001546:Bentonite