<p>Chronic Wasting Disease In Cervids: Prevalence, Impact And Management Strategies</p>

Abstract

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) that affects members of the cervidae family. The infectious agent is a misfolded isoform (PrPSC) of the host prion protein (PrPC). The replication of PrPSC initiates a cascade of developmental changes that spread from cell to cell, individual to individual, and that for some TSEs, has crossed the species barrier. CWD can be transmitted horizontally and vertically, and it is the only TSE that affects free-ranging wildlife. While other TSEs are under control and even declining, infection rates of CWD continue to grow and the disease distribution continues to expand in North America and around the world. Since the first reported case in 1967, CWD has spread infecting captive and free-ranging cervids in 26 states in the US, 3 Canadian provinces, 3 European countries and has been found in captive cervids in South Korea. CWD causes considerable ecologic, economic and sociologic impact, as this is a 100% fatal highly contagious infectious disease, with no treatment or cure available. Because some TSEs have crossed the species barrier, the zoonotic potential of CWD is a concern for human health and continues to be investigated. Here we review the characteristics of the CWD prion protein, mechanisms of transmission and the role of genetics. We discuss the characteristics that contribute to prevalence and distribution. We also discuss the impact of CWD and review the management strategies that have been used to prevent and control the spread of CWD.

Immunotherapy against Prion Disease

“…The public health concern about CWD is another reason to consider immunotherapy [46]. As of November 2019, CWD in free-ranging deer, elk, and moose has been found in at least 24 states in the United States and three provinces in Canada [47]. CWD has also been reported in reindeer and moose in Norway, Finland, and Sweden [48], as well as in South Korea following the importation of CWD-infected elk [49,50].…”

“…CWD has also been reported in reindeer and moose in Norway, Finland, and Sweden [48], as well as in South Korea following the importation of CWD-infected elk [49,50]. The incidence of CWD in free-ranging deer and elk is relatively low, but the prevalence may exceed 30% in endemic areas and can be as high as 80-90% in a captive herd [47,51,52]. So far, there is no evidence that CWD can be transmitted to humans [52,53].…”

Spatial population genetics in heavily managed species: Separating patterns of historical translocation from contemporary gene flow in white-tailed deer

“…Previous CWD research in WTD populations has focused on the prevalence of a polymorphism in the PRNP gene [responsible for the malformed protein product that constitutes the prion agent of CWD (Johnson et al, 2011;Race, Meade-White, Miller, Fox, & Chesebro, 2011;Rivera et al, 2019)]. Those WTD exhibiting a non-synonymous transition at amino acid residue 96 (from G to S) had decreased susceptibility to CWD.…”

Association of chronic wasting disease susceptibility with prion protein variation in white-tailed deer (Odocoileus virginianus)

“…Since then, CWD has spread to additional species and affects free-ranging Cervidae in 24 US states, two Canadian provinces, Norway, Finland, and Sweden [8]. Including captive populations, CWD has been reported in an additional two US states, a Canadian province, and South Korea [8,9]. In Illinois, CWD was first detected in free-ranging white-tailed deer (WTD) in 2002 [10] and has since expanded to 17 counties in northern Illinois.…”

“…As of 30 June 2018, the CWD prevalence rate for hunter-harvested deer across the affected counties is 1.07% for adult males and 0.54% for adult females, while the prevalence rate among adult deer taken by the Illinois Department of Natural Resources (IDNR) during targeted culling operations was 2.11% in 2018 [ 11 ]. Disease management strategies in Illinois have kept CWD prevalence rates at low levels since discovery [ 9 - 12 ].…”