CIDRAP report highlights gaps in CWD testing and human spillover preparedness
Chronic wasting disease has been prevalent in various cervid species across the United States and other countries since the late 1960s, but much about the neurodegenerative disease remains unknown.
A recently published report by the Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota highlights the gaps in research, testing, and response to chronic wasting disease (CWD) in cervid species, such as deer and the potential crossover to humans, other wildlife species, and livestock.
CWD is caused by prions, an infectious protein that affects deer and other cervid species neurologically and, once infected, is fatal within a couple of years. Cervids become infected by body fluid contact and environmental contamination after prions are shed onto plants or water sources.
“They develop this kind of chronic wasting syndrome that we call it, where they literally are unable to move,” Michael Osterholm, the CIDRAP director, said.
Since its discovery and first confirmed case in 1967 in Colorado, CWD has spread to 35 states across the U.S. and several international countries.
It has been prevalent in Minnesota for many decades, increasing in geographic range. As of the 2024 deer hunting season, the only area in the state without a confirmed CWD case is the northeast Arrowhead region. However, CWD testing is not mandatory or widely practiced in the northeast region.
“I think it’s just a matter of time before we see it throughout most of the state,” Osterholm said.
The concern among researchers, hunters, and the public is the potential spillover of CWD from cervids to humans.
“Up till now, we’ve not really had any evidence that that could happen, although we surely think it could,” Osterholm said. “We’re now seeing strains of this prion in these deer changing to the point of where we’re very concerned that it could be transmitting to humans.”
According to the CIDRAP report, physician recognition of prion diseases is limited because it is rare and has symptoms that overlap with other neurodegenerative diseases. In addition, the report stated, “the incubation period for CWD in humans is likely to be long (i.e., 10 years or more), so the clinical landscape will always lag behind the real-time transmission risk.”
Osterholm said that while there are no confirmed CWD cases in humans, more research is needed to study hunters and individuals who consume venison from a CWD-positive deer to understand the potential health implications fully.
The CIDRAP report identifies the necessary preparedness measures to expand CWD management and research beyond wildlife agencies, including public health.
“One of the things that really was apparent with our efforts here is that the wildlife folks were not talking to the production animal folks; we’re not talking to the human health folks very much,” Osterholm said. “We should all be working together on this.”
Another area for additional research and testing is the potential spillover of CWD to livestock. “CWD spillover could have far-reaching effects on the food supply, economy, global trade, and agriculture,” the report stated.
Osterholm said in Texas, there are confirmed cases of CWD spillover in feral pigs. “And if it can go to feral pigs, it surely can go into domestic pigs,” he said. “The implications for our agricultural industry are huge, absolutely huge.”
“Transmission of CWD to non-cervid production animals is of particular concern because it could lead to contamination of a local, regional, or globally distributed food supply,” the report said. “Investigating strain diversity and evolution is a primary focus of current research.”
Read the full CIDRAP ‘Chronic Wasting Disease Spillover Preparedness and Response: Charting an Uncertain Future’ report here.
WTIP’s Kalli Hawkins spoke with the CIDRAP Director, Michael Osterholm, about CWD, the challenges in testing, gaps in research, and the comprehensive CIDRAP report. The audio from the interview is below.
Kalli Hawkins January 25, 2025
