Chronic wasting disease (CWD) is a
prion disease that affects free-ranging and captive cervids, including mule deer, white-tailed deer, Rocky Mountain elk and moose. CWD-infected cervids have been reported in 14 USA states, two Canadian provinces and in South Korea. The possibility of a zoonotic transmission of CWD
prions via diet is of particular concern in North America where hunting of cervids is a popular sport. To investigate the potential public health risks posed by CWD
prions, we have investigated whether intracerebral inoculation of brain and spinal cord from CWD-infected mule deer transmits
prion infection to transgenic mice overexpressing human
prion protein with
methionine or
valine at polymorphic residue 129. These transgenic mice have been utilized in extensive transmission studies of human and animal
prion disease and are susceptible to BSE and vCJD
prions, allowing comparison with CWD. Here, we show that these mice proved entirely resistant to
infection with mule deer CWD
prions arguing that the transmission barrier associated with this
prion strain/host combination is greater than that observed with classical BSE
prions. However, it is possible that CWD may be caused by multiple
prion strains. Further studies will be required to evaluate the transmission properties of distinct cervid
prion strains as they are characterized.