injected with iiydrolyzed material died, wliile 15 

 out of 23 mice injected witli rendered material died 

 within about 244 days of injection. These results 

 demonstrate that hydrolysis is effective at destroying 

 infectious prions. Rendering, on the other hand, is 

 not as effective as hydrolysis and does not remove 

 all of the infectious material. 



Enzymatic Decontamination of Infectious Prion 

 Material— In 2007, NWRC scientists completed 

 an 18-month study testing the ability of two 

 enzymes to destroy the infectivity of prion material. 

 Enzyme 1 protected 57 percent of the mice tested 

 from becoming infected and developing CWD 

 and prolonged the time before the disease was 

 noted in the rest. The level of infectious material 

 destruction appears to be very high, almost to the 



point of complete removal of infectivity. Enzyme 

 2 also showed substantial reduction in disease 

 material under even less favorable digestion 

 conditions (i.e., lower temperatures). All negative 

 control mice survived the entire study period and 

 all positive controls developed the disease. With 

 modifications to the treatment conditions, complete 

 removal of infectious potential may be possible. It 

 is clear that enzymes will be a useful tool for the 

 decontamination of infectious prion material. 



Validation of a Live Test for CWD— In 2006, a 

 practical live test for CWD in elk was developed 

 by NWRC scientists in cooperation with CSU 

 and APHIS' Veterinary Services. Scientists are 

 continuing to refine the methods and are now 

 fully developing, evaluating, and validating a rectal 



It is likely that diseases can be transmitted when wild and captive elk come into contact through fences. 

 22 Developing Methods 



