Chronic wasting disease, a fatal and contagious illness affecting deer, elk, and moose, has spread to 36 U.S. states and is raising fears of a spillover to humans.
Todd Wilkinson reports for The Guardian.
In short:
- Chronic wasting disease (CWD) is an incurable prion disease that now infects wild and farmed cervids across the U.S., Canada, Scandinavia and South Korea.
- A 2025 expert report warns the U.S. is unprepared for the potential jump of CWD to humans, which could disrupt the food supply, economy, and public health systems.
- CWD prions persist in soil and can spread via carcasses and bodily fluids; feeding grounds and predator control worsen the disease's reach.
Key quote:
“CWD is a deathly serious public and wildlife health issue.”
— Michael Osterholm, epidemiologist and director of the University of Minnesota's Center for Infectious Disease Research and Policy
Why this matters:
Chronic Wasting Disease has crept across North America’s deer, elk, and moose populations for decades, but concern among scientists and health officials is reaching a new pitch. The disease is caused by misfolded proteins called prions — nearly indestructible agents that can contaminate not just animals, but the environment itself. Once present, they can linger in soil and plants, silently infecting herds and making containment nearly impossible. In states where hunting is both cultural tradition and food source, the implications are especially dire.
What alarms researchers most is the potential for CWD to jump the species barrier. While no human cases have been confirmed, parallels to mad cow disease, another prion illness, are hard to ignore. Hunters may be consuming infected meat without knowing it, as routine testing remains limited and uneven across states. Meanwhile, efforts to track the disease remain underfunded, even as it spreads to new areas.
Learn more: Assessing the human risk of 'zombie deer disease'
