THE HOST-RANGE OF CHRONIC WASTING DISEASE IS ALTERED ON PASSAGE IN FERRETS

Chronic wasting disease (CWD), a member of the transmissible spongifor m encephalopathies (TSEs), was first identified in captive mule and bl ack-tail deer in 1967 Due to the failure to transmit CWD to rodents, w e investigated the use of ferrets (Mustela putorius furo) as a small a nimal model of CWD. The inoculation of CWD into ferrets resulted in an incubation period of 17-21 months on primary passage that shortened t o 5 months by the third ferret passage. The brain tissue of animals in oculated with ferret-passaged CWD exhibited spongiform degeneration an d reactive astrocytosis. Western blot analysis of ferret-passaged CWD demonstrated the presence of PrP-res. Unlike mule deer CWD, ferret-pas saged CWD was transmissible to Syrian golden hamsters (Mesocricetus au ratus). Increasing the passage number of CWD in ferrets increased the pathogenicity of the agent for hamsters. This increase in host range o f a field isolate on interspecies transmission emphasizes the need for caution when assessing the potential risk of transmission of TSEs, su ch as bovine spongiform encephalopathy, to new host species. (C) 1998 Academic Press.