Date of this Version
Bartelt-Hunt SL, Bartz JC (2013) Behavior of Prions in the Environment: Implications for Prion Biology. PLoS Pathog 9(2): e1003113. doi:10.1371/journal. ppat.1003113
Emergence of Prion Diseases
Prion diseases are infectious, potentially zoonotic neurodegenerative diseases of animals including humans that are inevitably fatal and are caused by prions. Prions are comprised of a misfolded isoform of the normal prion protein, PrPC, into the infectious conformation, PrPSc . Of the known prion diseases, chronic wasting disease (CWD) of deer, elk, and moose is emerging. CWD was first identified in captive deer in the front range of Colorado and Wyoming in the 1960s and has since been identified in captive and free-ranging cervids in 20 states, two Canadian provinces, and South Korea (for latest disease distribution please see http://www. nwhc.usgs.gov/disease_information/chronic_wasting_disease/index. jsp).While there is evidence of the spread ofCWDalong known cervid home ranges, the mechanism underlying the emergence of CWD in geographically isolated areas is not understood. The prevalence of CWD within an affected population is generally lower than 5%; however, there are reports of incidence rates that approach 50%. Transmission of CWD can occur horizontally or through CWD contaminated environments, but the relative contribution of each mode in the overall transmission of CWD is unknown . Since effective control measures are not available, it is likely that CWD will continue to spread in North America. The effect of this on the wellbeing of the cervid population and the risk of transmission to other species is not known.