Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Schramm, P. T. Articles by Pedersen, J. A. Search for Related Content GeoRef GeoRef Citation

Potential Role of Soil in the Transmission of Prion Disease

¹ Molecular and Environmental Toxicology Center
² Program in Cellular and Molecular Biology
³ Animal Health and Biomedical Sciences
⁴ Nelson Institute for Environmental Studies
⁵ Department of Soil Science University of Wisconsin Madison, Wisconsin, 53706-1299, U.S.A. e-mail: japedersen@soils.wisc.edu

The first 20% of the full text of this article appears below.

	BACKGROUND ON PRION DISEASES

 
Transmissible spongiform encephalopathies (TSE), or prion diseases, are a family of inevitably fatal neurodegenerative disorders affecting a variety of mammalian species. These diseases include scrapie in sheep and goats; bovine spongiform encephalopathy (BSE, "mad cow" disease) in cattle; chronic wasting disease (CWD) in North American deer, elk and moose; transmissible mink encephalopathy; and Creutzfeldt-Jakob disease (CJD, sporadic, familial and variant forms) and kuru in humans. These diseases are characterized by long incubation periods, spongiform degeneration of the brain and accumulation of an abnormally folded isoform of the prion protein, designated PrP^Sc, in brain tissue (Prusiner 1998).

CWD and scrapie are the only TSEs that appear to be environmentally transmitted. Therefore, this chapter focuses primarily on these two TSEs. Scrapie has been known in sheep for at least 250 years (McGowan 1922). Most clinically infected sheep exhibit the obvious feature of excessive rubbing and scratching of the skin; the term "scrapie" derives from this symptom. The peak incidence of scrapie occurs in sheep three to four years of age although the earliest cases are seen at 18 months and the latest in animals older than 10 years (Dickinson 1976). The origin of the scrapie agent is unknown, but a familial pattern exists in natural sheep scrapie suggesting that genetics and, possibly, vertical transmission are important. Scrapie has a world-wide distribution and has been documented wherever sheep are raised, with the exception of Australia and New Zealand.

CWD was first identified at a Colorado research facility in 1967 (Williams and Young 1980) and has since been identified in captive cervid populations in Wyoming, Wisconsin, Saskatchewan, South Dakota, Oklahoma, New York, Nebraska, Montana, Minnesota, Kansas and Alberta (Fig. 1). In the free-ranging cervid population, CWD has been found in Wyoming, Wisconsin, Utah, South Dakota, Saskatchewan, . . . [Full Text of this Article]

This article has been cited by other articles:

				N. Sahai, M. A. A. Schoonen, and H. C. W. Skinner The Emergent Field of Medical Mineralogy and Geochemistry Reviews in Mineralogy and Geochemistry, January 1, 2006; 64(1): 1 - 4. [Full Text] [PDF]