Increased attack rates and decreased incubation periods in raccoons with chronic wasting disease passaged through meadow voles

Abstract

Chronic wasting disease (CWD) is a naturally-occurring neurodegenerative disease of cervids. Raccoons ( Procyon lotor ) and meadow voles ( Microtus pennsylvanicus ) have previously been shown to be susceptible to the CWD agent. To investigate the potential for transmission of the agent of CWD from white-tailed deer to voles and subsequently to raccoons, we intracranially inoculated raccoons with brain homogenate from a CWD-affected white-tailed deer (CWD Wtd ) or derivatives of this isolate after it had been passaged through voles 1 or 5 times. We found that passage of the CWD Wtd isolate through voles led to a change in the biologic behavior of the CWD agent, including increased attack rates and decreased incubation periods in raccoons. A better understanding of the dynamics of cross-species transmission of CWD prions can provide insights into how these infectious proteins evolve in new hosts.