Sensitive, non-invasive detection of chronic wasting disease in wild and captive white-tailed deer using fecal volatile profiling

Chronic wasting disease (CWD) is a universally fatal, transmissible prion disease affecting cervids. Primarily found among deer populations in North America, the disease has spread across the continent and made forays into Europe and Asia as well. Currently, accurate methods for detecting CWD infection require postmortem dissection of the lymph nodes and brainstem of affected animals. New, high-sensitivity methods of identifying CWD in living animals are sorely needed to help curb the spread of this devastating disease in captive and wild deer. Here, we use two-dimensional gas chromatography-mass spectrometry (GCxGC-MS) to detect volatile organic compounds (VOCs) released from feces of white-tailed deer (WTD) for differentiation of the feces of CWD-negative and CWD-positive animals. We report 4 discrete VOCs in captive WTD and 10 discrete VOCs in wild WTD, with which we can discriminate CWD-positive and CWD-negative samples. Additionally, we evaluate the ability to detect biomarkers associated with CWD early during disease progression, by comparing samples from the early stage of infection with samples from the late stage and uninfected WTD. Our data suggest that detection of VOCs from the feces of WTD-both in captive and wild populations-can serve as a highly sensitive and non-invasive technique for identifying CWD infection in living animals.IMPORTANCEChronic wasting disease (CWD) is a deadly, transmissible prion disease of cervids. The spread of CWD is increasing among both wild and captive deer populations; however, the options to detect in living animals are limited. Diagnosing CWD early would allow more effective control over the spread between animals and contamination of the environment. Our research presents a method of determining CWD infection through the detection of disease-associated odor molecules in the feces of affected deer. This methodology lays the foundation for rapid, non-invasive diagnosis of CWD in living white-tailed deer, allowing for the development of tools to enhance control of this devastating disease's spread among both captive and wild populations.