Chronic wasting disease (CWD) in cervids and the consequences of a mutable protein conformation

Authors: Silva, Christopher - Chris

Submitted to: ACS Omega
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/18/2022
Publication Date: 4/4/2022
Citation: Silva, C.J. 2022. Chronic wasting disease (CWD) in cervids and the consequences of a mutable protein conformation. ACS Omega. 7(15):12474–12492. https://doi.org/10.1021/acsomega.2c00155.
DOI: https://doi.org/10.1021/acsomega.2c00155

Interpretive Summary: Chronic wasting disease (CWD) is a prion disease of deer and elk. It is the only prion disease spread among wild animals through their natural behaviors. As a result, CWD has spread to 29 states, four Canadian provinces, and South Korea. The CWD recently found in Norway, Sweden, and Finland appears to have originated independently. CWD prions cause disease by inducing a normal cellular protein to adopt the prion shape. Distinguishing between the normal cellular protein and the prion shapes is difficult. CWD can be both sporadic and transmissible, which makes it difficult to eradicate. CWD prions can evolve to respond to natural selection pressures. This means that CWD prions of the future will be different from those of the present. Millions of Americans hunt and harvest nearly 6 million deer each year. CWD poses an uncertain threat to a significant segment of the American food supply. The circulating CWD strains do not infect people. If a CWD strain that infected people emerged, then it could substantially impact American hunters and consumers of game meats.

Technical Abstract: Chronic wasting disease (CWD) is a prion disease of cervids (deer, elk, moose, etc.). It spreads readily from CWD-contaminated environments and among wild cervids. As of 2022, North American CWD has been found in 29 states, four Canadian provinces and South Korea. The Scandinavian form of CWD originated independently. Prions propagate their pathology by inducing a natively expressed prion protein (PrPC) to adopt the prion conformation (PrPSc). PrPC and PrPSc differ solely in their conformation. Like other prion diseases, transmissible CWD prions can arise spontaneously. The CWD prions can respond to selection pressures resulting in the emergence of new strain phenotypes. Annually, 11.5 million Americans hunt and harvest nearly 6 million deer, indicating that CWD is a potential threat to an important American food source. No tested CWD strain has been shown to be zoonotic. However, this may not be true for emerging strains. Should a zoonotic CWD strain emerge, it could adversely impact the hunting economy and game meat consumers.