We have been writing about his since 2006 on this blog. Recently, I linked to a site I named “How Now, Mad Cow“on my blogroll. RM
Mysterious, fatal disease bound for elk feedgrounds. A cousin of mad cow, chronic wasting disease is a worry for Jackson Hole’s wildlife economy. By Cory Hatch. Jackson Hole News and Guide.
Comments
This is the most disturbing aspect of this disease:
A recent study showed that the infectious prions bind to the soil, increasing their ability to infect.
The arrival of chronic wasting disease is sort of like the arrival of radioactive pollution — permanent contamination
This will just provide the livestock industry another justification to kill more wildlife.
well….Ralph, you would be right if you consider concentrated prion proteins (much like anthrax spores) that accumulate in areas of high infection (such as a fenced area in a vet school or a feed lot for elk in Wyoming) but generally speaking, in the wild, with normal migration patterns of animals, I think you would be hard pressed to argue a soil infection of an animal versus animal to animal contact. But I certainly see your point that feed lots can concentrate the disease and hold it for long periods of time. Yet another argument for how wild infection rates of CWD can be lowered by doing away with artificial aggregations of animals. Maybe that is how Tuners bison got so infected: they were all standing around in each others crap.
john weis,
My comment about prions and soil were based on what I read in this article.
Soil particles found to boost prion’s capacity to infect. July 6, 2007
Ralph, I read over the Plos paper that the summary was based on. From that paper and a few previous from the same group, they have shown that infected brain homogenate (and other preps) can be mixed with soil and that interaction actually makes the brain material more infectious than alone. How and why that actually happens is another story, but I was struck with wondering how such complexes get formed in the first place much less transmitted to an uninfected animal.
I think it is obvious that an elk pen or feedlot that can concentrate animals in a small area could create a high enuf prion concentration in the dirt as to increase transmission, and so such concentrations of animals should be avoided.
But what about in the wild, where we see a slow moving front of infection (in Utah, from Colo moving west from Vernal area infections)? We know from others data that saliva is a potent means of transmission, but do elk/deer really spit on each other enuf to cause an infection?
A different model of transmission might be via natural salt licks. Deer and elk migrate along corridors that include such mineral outcroppings, and we know know that prions like to stick to charged particles (which a salt deposit would certainly include). So is it possible that wild transmissions are via prion deposits from infected animals on salt deposits that are then licked and taken up by uninfected animals?
Oh, and i forgot to add that that research was funded by the Department of Defense. Amazing what the DOD will do to keep the greenbacks flowing. I guess making marine eat infected brains infected with Kuru is a major biological warfare concern.
john weis,
I think you are correct about deer and elk visiting salt licks and also using the same migration corridors. This would be much worse if it got to the feedgrounds. They might have to be fenced off as permanently contaminated zones.
Deer and elk do lick each other.
It seems to me that both could be a method of spreading infection.