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Soil clay content underlies prion infection odds.

David Walter W, Walsh DP, Farnsworth ML, Winkelman DL, Miller MW - Nat Commun (2011)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: United States Department of the Interior, United States Geological Survey, Colorado Cooperative Fish and Wildlife Research Unit, Fort Collins, Colorado 80523-1484, USA.

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.

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Related in: MedlinePlus

Spatial relationships between soil clay content and prion disease in mule deer.(a) The average percentage of clay-sized particles contained in soils3748 within the 9 km2 area surrounding a sampled deer strongly influenced its odds of prion infection in northcentral Colorado, USA (Table 1). (b) A similar relationship between soil clay content and the odds of prion infection also was evident in deer sampled from northwestern Colorado (Table 1). In both panels, dots (•) represent locations of prion-infected deer presence and crosses (×) represent locations of apparently uninfected deer presence.
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f1: Spatial relationships between soil clay content and prion disease in mule deer.(a) The average percentage of clay-sized particles contained in soils3748 within the 9 km2 area surrounding a sampled deer strongly influenced its odds of prion infection in northcentral Colorado, USA (Table 1). (b) A similar relationship between soil clay content and the odds of prion infection also was evident in deer sampled from northwestern Colorado (Table 1). In both panels, dots (•) represent locations of prion-infected deer presence and crosses (×) represent locations of apparently uninfected deer presence.

Mentions: The effect of soil clay content on the odds of infection was most evident in northcentral Colorado (Fig. 1a) where prion disease has occurred since at least from the 1960s (ref. 9,30). In this area, the average soil clay content in the vicinity of sampled deer ranged from 4 to 32% and the odds of prion infection increased by 8.9% for every 1% increase in soil clay (odds ratio 1.089; 95% credible interval (CI) 1.038–1.141). Percent clay within the vicinity of sampled deer was by far the most important variable in the best model to explain infection probability (Table 1). Moreover, percent clay was included in the top four models to explain infection probability (Supplementary Table S1). These four models clearly represented the best fitting of those considered (Supplementary Table S1, 'Weights'), providing strong evidence that including the percent clay parameter enhanced these models' abilities to explain the underlying infection-generating process far better than similar models in the candidate set lacking the parameter293132.


Soil clay content underlies prion infection odds.

David Walter W, Walsh DP, Farnsworth ML, Winkelman DL, Miller MW - Nat Commun (2011)

Spatial relationships between soil clay content and prion disease in mule deer.(a) The average percentage of clay-sized particles contained in soils3748 within the 9 km2 area surrounding a sampled deer strongly influenced its odds of prion infection in northcentral Colorado, USA (Table 1). (b) A similar relationship between soil clay content and the odds of prion infection also was evident in deer sampled from northwestern Colorado (Table 1). In both panels, dots (•) represent locations of prion-infected deer presence and crosses (×) represent locations of apparently uninfected deer presence.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3105318&req=5

f1: Spatial relationships between soil clay content and prion disease in mule deer.(a) The average percentage of clay-sized particles contained in soils3748 within the 9 km2 area surrounding a sampled deer strongly influenced its odds of prion infection in northcentral Colorado, USA (Table 1). (b) A similar relationship between soil clay content and the odds of prion infection also was evident in deer sampled from northwestern Colorado (Table 1). In both panels, dots (•) represent locations of prion-infected deer presence and crosses (×) represent locations of apparently uninfected deer presence.
Mentions: The effect of soil clay content on the odds of infection was most evident in northcentral Colorado (Fig. 1a) where prion disease has occurred since at least from the 1960s (ref. 9,30). In this area, the average soil clay content in the vicinity of sampled deer ranged from 4 to 32% and the odds of prion infection increased by 8.9% for every 1% increase in soil clay (odds ratio 1.089; 95% credible interval (CI) 1.038–1.141). Percent clay within the vicinity of sampled deer was by far the most important variable in the best model to explain infection probability (Table 1). Moreover, percent clay was included in the top four models to explain infection probability (Supplementary Table S1). These four models clearly represented the best fitting of those considered (Supplementary Table S1, 'Weights'), providing strong evidence that including the percent clay parameter enhanced these models' abilities to explain the underlying infection-generating process far better than similar models in the candidate set lacking the parameter293132.

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: United States Department of the Interior, United States Geological Survey, Colorado Cooperative Fish and Wildlife Research Unit, Fort Collins, Colorado 80523-1484, USA.

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.

Show MeSH
Related in: MedlinePlus