It’s the time of year when thoughts are on hunting. For almost 80% of us, that means we’ve been pursuing deer even though diseases like chronic wasting disease (CWD) continue to spread.
The disease has been detected in 30 states, four Canadian provinces, three European countries, and South Korea. In some places, it’s likely endemic. While the likelihood of transmission to humans remains low, an increasing number of laboratory experiments suggest that the likelihood of this happening is increasing. Perhaps more troubling, inconsistent messaging, cost, and “disease fatigue” have led a growing number of hunters to disregard the risks. In Wisconsin, a majority of hunters who receive a positive test likely consume the infected venison anyway.
Luckily all the news isn’t doom and gloom.
The University of Minnesota School of Veterinary Medicine has developed a field portable definitive test for CWD that one day soon could be available at deer check stations or in veterinary clinics. This development could make testing universally and conveniently available while reducing testing costs to agencies (the national testing cost/sample is $144, while the averages in Wisconsin, Minnesota, and Michigan are $91.34, $93.33, and $167.64, respectively).
As well, because CWD jumps boundaries, state agencies actively are collaborating to develop consistent, efficient, and economical best practices. Several of these collaborative efforts deserve special mention.
One is the Regional CWD Adaptive Management Framework, an effort made possible with funding appropriated by the Michigan state Legislature in 2018. Among the member agencies are the National Wildlife Health Center, Association of Fish and Wildlife Agencies, and Cornell and Michigan State universities. State agency partners include the Michigan, Minnesota, Iowa, and Wisconsin DNRs.
Models have been developed to characterize how, when, and where CWD outbreaks are most likely to occur. And several Midwest states are now using them to strategically direct surveillance efforts. To facilitate application, user-friendly interface dashboards (maintained as the CWD Data Warehouse) allow agency managers to input the most current harvest data and assess the effectiveness of CWD response strategies in various public- and private-land settings.
Another is SOP4CWD, a growing national partnership that currently includes 26 states and Ontario. This effort is linked to the Adaptive Management Framework modeling applications, and focuses on information sharing and integration. Of special interest to the partners are the relative contributions of direct and indirect (i.e., environmental, and anthropogenic) sources of CWD infection.
The collaboration also is focused on how to compensate for statistically insufficient sampling intensities (despite enormous and expensive efforts, state agencies rarely if ever employ sampling at an intensity to statistically detect very low levels of disease).
Finally, the CWD Alliance has assembled and is maintaining a website that provides a public facing and continually refreshed presentation of CWD regulations for every state and Canadian province. SOP4CWD and the Adaptive Management Framework collaborators are in discussions with the Alliance to include their products on the Alliance website so that it provides a “one-stop shop” for hunters and managers.
In the end, it’s time to admit that CWD is here to stay. The disease is exerting enormous and ultimately unsustainable financial pressure (nationally, in excess of $21 million) on agencies, to say nothing of its effect on hunters and free-ranging populations of deer and elk.
Given what we know about CWD prevalence and spread, the most likely future is one where all the Lower 48 will become CWD-positive in the next five to 10 years. What this means (using today’s dollars without inflation) is that the national cost will increase to at least $34,560,000.
Arguably, whatever can be done should be done to contain costs. Otherwise, challenges like habitat resilience in the face of climate change, or mounting invasive species threats, will go under-funded.
New CWD testing regimes, landscape level cross-jurisdictional collaborations, and enhanced biosecurity practiced by hunters before disease is found are all essential to keep CWD at acceptably low levels and to protect North American big game hunting traditions.
Editor’s note: Russ Mason, Ph.D., is the DNR executive in residence and adjunct professor in the College of Agriculture and Natural Resources at Michigan State University.