CWD's Silent Spread: Prions, Zombie Deer, and Uncertain Human Risk

Chronic Wasting Disease (CWD) is a fatal prion disease spreading through North American deer populations, with infected animals able to shed prions and transmit before symptoms appear (incubation about 18–24 months). Prions persist in the environment, making containment almost impossible. While there are no confirmed human cases, lab studies show potential transmission to humans, prompting health agencies to advise hunters to test venison and avoid high-risk tissues. By August 2025, CWD has been detected in at least 36 U.S. states, five Canadian provinces, and in Norway, Sweden, Finland, and South Korea. Estimates suggest 7,000–15,000 CWD-infected animals are eaten annually by humans, a figure that could grow about 20% per year in heavily affected areas. Eradication is not feasible; disease may cause population declines, so surveillance and testing are crucial.