Monday, February 27, 2006

Chronic Wasting Disease

Every hunter of deer and elk in the central Rockies is aware of CWD, a "mad cow'' - type prion disease that is spreading there. Ted Kerasote sent this disturbing link to a study that indicates muscle meat may be infective.

However, this week he sent a clarification by the dean of hoofed mammal studies, Valerius Geist, who wrote:

"The discovery that CWD prions are in meat, comes at no surprise. The fact that transgenic mice - made genetically susceptible to CWD will develop CWD when fed muscle tissue, is also no surprise. There is also an old study, in vitro (test tube) that shows that CWD prions convert human prions to the malignant state at about 7% infectivity (CJD prions, under the same in vitro conditions, convert health pre-pirons at 100% into malignant one). That's in vitro, not in vivo. Something appears to prevent in vivo infections in humans.

"That's the conclusion today, meaning that CWD infected meat is safe to eat. Except, we suspect, for some unknown human genotype that might not enjoy such genetic protection. So far, such a human has not been found. Also, if BSE converts preprions in transgenic mice (with implanted genes producing human pre-prions in these mice) into classical CJD, then there is a real likelihood that CJD cases triggered by CWD prions cannot be traced to such! CWD may infect humans, but there is no smoking gun!"

Hmmm. I think I'll still not shoot a staggering deer...

3 comments:

Anonymous said...

Steve, is this Ted Kerasote the same that wrote in Sports Afield magazine some 30 years ago? I used to have a subscription back then and read his articles on the outdoors. Wow!

JC/SCL(Santiago-Chile)

Steve Bodio said...

Same Ted-- still hunting and still writing. He has a book on dogs coming out next year.

Mary Strachan Scriver said...

The radio reported not long ago that elk kept in a pen where there had previously been infected (not sure that's the right word for a prion, which is not exactly infectious) elk DID develop the same disorder. One of the precursors or pre-disposers for this affliction is evidently crowding.

Prairie Mary