A new report from the National Academies of Sciences, Engineering, and Medicine sheds light on the persistent challenges of managing chronic wasting disease (CWD) in deer, elk, and moose populations across the United States. Dr. Tiffany Wolf, from the College of Veterinary Medicine at the University of Minnesota, served on the report's authoring committee.

Since it was first detected in Colorado in 1967, CWD has spread to affect free-ranging and captive cervid populations across North America and beyond—including Minnesota, where it was first detected in 2002. This fatal prion disease impacts deer, elk, moose, and reindeer, causing neurological damage, behavioral changes, and ultimately death. The insidious nature of CWD, with its long incubation period and environmental persistence, poses significant challenges for wildlife managers. Without strong management, CWD can lead to population declines, ecosystem disruption, and potential economic impacts related to hunting and wildlife tourism.

At the request of Congress, the report was commissioned by the U.S. Fish and Wildlife Service, U.S. Geological Survey of the Department of the Interior, and the Animal and Plant Health Inspection Service of the United States Department of Agriculture to synthesize the current understanding of CWD and to identify knowledge gaps hindering effective management strategies. With CWD continuing to spread, understanding the complexities of its transmission and spread is crucial for protecting cervid populations and ecosystems.

Major findings from the report include the following:

• CWD spread and impact: CWD continues to spread in both captive and free-ranging cervid populations, and in areas with established infections population declines have been observed.
• Transmission pathways: Gaps remain in fully understanding all CWD transmission routes, especially the relative importance of direct contact, indirect environmental contamination (via soil, water, and plants), and maternal transmission.
• Surveillance and monitoring: Current surveillance and monitoring programs vary widely in intensity and methodology across states and other jurisdictions, hindering accurate assessment of CWD prevalence and distribution at a national level. Enhanced, standardized approaches are needed.
• Management effectiveness: The effectiveness of common CWD management strategies—including culling, movement restrictions, and hunting regulations—is still debated, and more rigorous, data-driven evaluations are needed to determine their long-term impact on disease prevalence and spread.

This report is intended to serve as a crucial resource for policymakers, wildlife managers, and researchers, and is expected to inform the work of a future task force that will be charged with developing a national strategy for combating CWD.

Wolf's participation on the committee highlights the University of Minnesota's commitment to addressing critical wildlife health issues. Her expertise in wildlife disease ecology and her experience in the field was invaluable to the report's development. 

"We have a lot of implicit and anecdotal knowledge about CWD, but it's crucial to move that into the realm of public, peer-reviewed research," Wolf says. "This allows it to be examined, tested, shared, and used to better inform our understanding and control of the disease."

In addition to the need for more formal research, Wolf notes the potential for making better use of existing data: "There's a lot of data collected by agencies over time that could greatly improve our ability to assess and mitigate CWD. To effectively utilize this data, we need to foster more data sharing and collaboration across all levels." 

This collaborative approach is at the heart of the University's ongoing efforts to help combat CWD. Wolf and her partners at the CVM’s Minnesota Center for Prion Research and Outreach (MNPRO) conduct ongoing environmental research, with forthcoming studies examining prion persistence in soils, transport by water, and contamination of food processing equipment. They continue to develop and validate technologies for antemortem animal testing, including research related to on-the-ground CWD testing. Additional MNPRO partnerships focus on mitigations related to carcass disposal and environmental contamination.

Find the full report from the National Academies here, and view a recorded webinar from the authoring committee here.