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 post-mortem dissection of the lymph nodes and brainstem of affected animals. New, high-sensitivity methods of detecting CWD in living animals are sorely needed to help curb spread of this devastating disease in farmed and wild deer. Here, we use two-dimensional gas chromatography-mass spectrometry (GCxGC-MS) to detect volatile organic compounds (VOCs) released from the feces of white-tailed deer (WTD) for differentiation of the feces of CWD-negative and CWD-positive animals. We report four discrete VOCs in captive WTD and ten discrete VOCs in wild WTD, with which we can discriminate CWD-positive and CWD-negative samples. Additionally, we evaluate the ability to detect CWD early during disease progression, by comparing samples from the early stage of infection with samples from 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.