CWD prions are present in the blood of healthy-appearing, naturally infected free-ranging white-tailed deer.

Chronic wasting disease (CWD) is an emergent, fatal prion disease in deer, elk, and moose that is recognized in 37 U.S. states, impacting $447 billion in annual wildlife activities and cervid farming industries. The continued detection of CWD in new geographic areas supports the need for the development of sensitive antemortem diagnostics capable of detecting CWD during the early stages of disease. Early detection will identify infected animals in the initial stages of prion shedding, helping to curtail further spread through improved surveillance and cull programs. Current CWD diagnostics, while providing valuable insights to our understanding of the magnitude of the disease, fall short in their ability to detect low concentrations of prions associated with nascent infections. Here we analyzed blood buffy coat cells collected from free-ranging white-tailed deer (WTD) (Odocoileus virginianus) in CWD endemic regions by a modified amyloid amplification assay to probe for the presence of blood-borne prions in naturally exposed deer. Our findings provide evidence that prions can be detected in the blood of healthy-appearing, naturally exposed and infected free-ranging WTD. These findings provide a tool for improved surveillance, herd management, and future studies to reveal therapeutic targets for this and related protein misfolding disorders.