Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE), or prion disease, of North American deer, elk and moose (cervids) (Williams 2005). Other TSEs include Creutzfeldt-Jakob disease in humans, bovine spongiform encephalopathy (“mad cow” disease) in cattle, and scrapie in sheep and goats. TSEs are inevitably fatal, progressive neurodegenerative diseases with long incubation periods and no known cure (Vallabh et al., 2020). Although CWD was initially isolated to the front range of the Rocky Mountains in the 1970s, since the early 2000s, CWD has expanded to include 35 U.S. states, four Canadian provinces, Scandinavia, and South Korea. The geographic range of the disease continues to grow, prevalence is increasing, and the disease has acquired new hosts (viz. moose and reindeer; Baeten et al. 2007, Benestad et al. 2016). In addition to affecting wild cervid populations, CWD in North America poses a potential risk to the agricultural industry, outdoor recreation, and human health. In states where CWD is established, it has emerged as a major threat to cervids in some areas, reducing the health of deer populations and causing long-term population decline (Edmunds et al. 2016, Gross and Miller 2001, Manjerovic et al. 2014). As CWD directly threatens free-ranging North American cervid populations, it can challenge the fiscal foundations of wildlife conservation in the U.S. Sales of deer hunting licenses constitute a large proportion of annual revenue supporting conservation and management programs across taxa. Declines in these revenues due to CWD threatens the financial cornerstone of state fisheries and wildlife programs. Transmission to humans has not been documented, but the Centers for Disease Control and Prevention advises hunters to not consume the meat of infected animals as CWD is a prion disease like bovine spongiform encephalopathy (BSE). BSE does infect humans, resulting in fatal human prion disease (CDC 2017). Uncertainties about human and livestock susceptibility, environmental contamination, and the ability of plants to accumulate the disease agent raise food and feed safety concerns (Hamir et al., 2011; Moore et al., 2017; Race et al 2009; 2018; Marsh et al., 2005; Pritzkow et al., 2015). Finally, emerging evidence is increasing concern that CWD may pose a risk to human health, and even perceptions that humans may become infected will have dramatic ecological and social consequences.

The infectious agent of CWD is a prion, an infectious, misfolded form (denoted as PrPCWD or PrPSc) of the normally benign prion protein (denoted as PrPC). Misfolded prion protein accumulates in the brainstem and lymphatic tissue of infected animals, and to a lesser extent in muscle and other tissues (Sigurdson et al. 2002, Angers et al. 2006, Henderson et al. 2015a, Spraker et al. 2015, Davenport et al. 2018, Otero et al. 2019). The disease propagates via a process in which infectious PrPCWD templates the conformational conversion of PrPC into PrPCWD (Lansbury & Caughey, 1995). This templating property of prions has been exploited to develop a variety of amplification assays that can be used to detect prions in tissues, secretions, excreta, and environmental samples (Haley et al. 2012, Henderson et al. 2015b, Pritzkow et al. 2015, Denkers et al. 2016, Henderson et al. 2017, Plummer et al. 2018 Ferreira & Caughey, 2020).

Chronic wasting disease is transmitted directly through animal-to-animal contact and indirectly through contact with contaminated environments (Miller et al. 2004). Infected deer shed prions through secretions and excreta (Miller et al. 2004, Mathiason et al. 2006, Safar et al. 2008, Haley et al. 2009, Tamgüney et al. 2009), and human-facilitated movement of infected live deer, animal parts and/or carcasses contributes to the geographic spread of CWD. Prion shedding from infected animals is not yet fully understood. CWD prions are shed throughout the incubation period of the disease but not necessarily in a consistent manner (Cheng et al, 2019; Denkers et al., 2024). Although there is some data on relative amounts of CWD prion infectivity in secretions/excreta (relative to infectivity in the brain), the link between detection of CWD prions in excreta/secreta and infection is poorly understood (i.e., is the titer of prions in saliva sufficient to cause infection in another cervid?). Also, transmission rate and mode for CWD have not been determined (Almberg et al. 2011, Smolko et al., 2021). Surveillance and epidemiological models specific to CWD and deer in highly productive habitats of the Midwest and Northeast suggest the disease is in early- to mid-stages of infection (Williams et al. 2014; Bondo et al., 2024; Evans et al., 2016; Hefley et al., 2017; Manjerovic et al., 2024). Initial studies suggest that CWD prions persist at various levels in the environment, at as yet undetermined titers, hindering our understanding of how and where environmental transmissions may occur (Plummer et al. 2018, Kuznetsova et al. 2024, Huang et al. 2024).

Prions shed into the environment remain infectious for years (Brown & Gajdusek. 1991, Miller et al. 2004, Georgsson et al. 2006, Seidel et al. 2007). These prions are remarkably resistant to most inactivation procedures that are effective against conventional infectious agents (e.g., many chemical disinfectants, autoclaving under conventional conductions, ionizing radiation, desiccation; Taylor 1999, Colby and Prusiner 2011). However, some treatments are effective, at least in laboratory settings (e.g., concentrated hypochlorous acid, sodium hydroxide, peroxymonosulfate, humic acid; Taylor 1999, Chesney et al. 2016, Williams et al. 2019, Giachin et al., 2014, Kuznetsova et al., 2018). No cure exists for CWD and non-management options (i.e., environmental decontamination and/or vaccines)  for disease mitigation have failed to show efficacy. Deer shed prions long before they manifest any outward signs of CWD (e.g., emaciation, disorientation, fearlessness, paralysis; Henderson et al. 2015). Therefore, reducing environmental contamination would benefit from detection and removal of diseased deer from the landscape well before clinical disease signs are exhibited.

Benefit of a Multistate Effort. Chronic wasting disease is distributed widely in North America, affects multiple cervid species, and does not respect jurisdictional boundaries. Research across multiple disciplines is needed to fully address the complexities of CWD and acquire the knowledge needed to limit or eliminate its growth and spread. A multistate CWD effort to coordinate research across jurisdictions would be beneficial for several reasons.

•   The ecology of CWD differs across the regions and jurisdictions in which it occurs due to variation in species, climate, surficial geology, habitat, and land use.


•   Host prion protein genotype (PRNP) distribution varies geographically. While no genotype is known to confer complete resistance to CWD, susceptibility to the disease depends on PRNP genotype (Johnson et al. 2006). Host PRNP genotype can affect management strategies.


•   Different strains of CWD exist and can be distinguished by the length of incubation period, as well as biological and biochemical properties. There is, to date, no rapid means of distinguishing many strains. Different CWD prion strains may occur in different geographic areas due to differences in cervid species that are present, and different allelic variations in PRNP. Prion shedding into the environment by infected individuals may differ in magnitude or in dynamics by CWD strain (or host genotype). Strains may differ in their zoonotic and cross-species potential and can affect management strategies.


•   A multistate effort facilitates the coordination of resources. Resources include funding for joint research efforts, sources of negative control animals or tissues, a clearinghouse for reference samples, large-scale research facilities, and increased capacity through a human resource network.


•   Jurisdictions impacted by CWD differ in their surveillance approaches. Standardization across jurisdictions would facilitate data sharing and increase epidemiological understanding of CWD dynamics.


•   Jurisdictions impacted by CWD differ in their legal authorities to minimize spread and resulting policy or management responses. Multi-state research provides the opportunity to assess the effectiveness of different regulatory strategies.


•   Disease management activities (or lack thereof) in one jurisdiction can affect the spread of the disease in another. Coordination across jurisdictional boundaries will improve the efficacy of disease surveillance and management and can enhance consistency and coordination between jurisdictions as well as accelerate learning about effective management strategies.

State and federal policies require public support and, frequently, funding for implementation. Given emerging research and perceptions around human health risk, as well as the growing footprint of CWD and CWD-related management, public health departments, natural resource agencies, and agricultural agencies are becoming increasingly involved with communication and public engagement regarding CWD. Understanding public attitudes, values, risk perceptions, and associated behavior will be critical for the development of socially accepted disease response strategies and effective strategies for addressing CWD. This multistate research project would continue our previous successes at facilitating sharing of knowledge, data and resources, promoting interdisciplinary collaboration among researchers and managers in different jurisdictions, and serving as a vehicle through which to communicate research and management priorities to national decision-makers. The multistate project will continue to foster information exchange among universities and researchers with common goals, but with different backgrounds and knowledge bases. Increased collaboration improves research quality and avoids duplication of work at a critical time when effective solutions are needed quickly. Although the current multistate project has improved collaborative efforts, research on and management of CWD across North America is still fragmented and minimally coordinated leading to issues of data comparability, duplication of effort, and concerns about the validity of measurements. This proposed multistate project continues to build on the successes of the previous 5 years and would continue to improve the quality of CWD research and management nationally.

Contributions of the Participating Agricultural Experiment Stations. Nearly half of the current project membership is associated with State Agricultural Experiment Stations. These 32 participants serve on the executive committee, serve as leads of the objectives, and actively participate in the collaborative publications, communications, and project meetings. These members come from the following 14 institutions:

University of Arkansas

Colorado State University

University of Georgia

Iowa State University

Michigan State University

University of Minnesota

Mississippi State University

University of Missouri

Cornell University

The Pennsylvania State University

South Dakota State University

University of Tennessee

Texas A&M University-Kingsville

University of Wisconsin