Advancing the Use of RT-QuIC for Applications in CWD Management

Science Center Objects

Chronic wasting disease (CWD) is an emerging infectious disease that is fatal to free-ranging and captive animals in Cervidae, the deer family. The development of the real-time quaking-induced conversion (RT-QuIC) assay has the potential to transform laboratory research of prions and provide new opportunities for improved surveillance and management.

A white-tailed deer fawn taking refuge in vegetation.

A white-tailed deer (Odocoileus virginianus) fawn taking refuge in the vegetation. (Credit: Daniel Walsh, USGS. Public domain.)

However, the widespread application of RT-QuIC has been hampered by 1) the lack of well-characterized reference samples to ensure proper assay functioning, identify optimal tissues for ante-mortem sampling, and determine biological relevance of results and 2) the absence of an appropriate modeling framework to leverage the information produced by RT-QuIC. In collaboration with the University of Wisconsin, state and federal partners, the USGS National Wildlife Health Center (NWHC) is working to fill these gaps by using RT-QuIC to fully characterize a range of biological tissues, body fluids, and excreta that are CWD-positive and -negative and comparing those results against the gold standard animal bioassay (a transgenic mouse bioassay).  NWHC is also building a modeling framework that will help managers determine appropriate control strategies by assessing the relative importance of environmental transmission, as measured by RT-QuIC, in CWD dynamics. The availability of reference samples and a robust modeling framework for CWD diagnostic labs and managers will help promote the rigorous application of RT-QuIC, identify optimal tissues for ante-mortem sampling, assess biological relevancy of findings, and provide a mechanism to leverage RT-QuIC information to aid CWD control efforts.