Insights Into Animal Diseases

A new study says the spread of animal sicknesses such as Chronic Wasting Disease in deer may
happen more easily because of the way a protein binds to soil. Chuck Quirmbach reports:

Transcript

A new study says the spread of animal sicknesses such as Chronic Wasting Disease in deer may
happen more easily because of the way a protein binds to soil. Chuck Quirmbach reports:


Scientists have known that when an infected animal puts prions, or abnormal protein agents, in
soil the prions can stay alive for a long time. A study has looked at different types of common
soil minerals and found that a type of clay is an especially good binding agent for the prions.


University of Wisconsin researcher Judd Aiken says the link is so good that there’s a much higher
risk of the infection spreading when another animal grazes in the area:


“There was an enhancement of infectivity and we’re estimating roughly a 700-fold enhancement
of infectivity.”


Aiken says it might mean that government efforts to stop the spread of deadly animal brain
diseases like Chronic Wasting Disease in deer or scrapie in sheep may only be as effective as the
type of soil where the animals live.


For The Environment Report, I’m Chuck Quirmbach.

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Could Humans Get Chronic Wasting Disease?

  • A deer wasting away from Chronic Wasting Disease. (Photo courtesy of Michigan's Department of Natural Resources.)

A disease that infects deer and elk has been alarming wildlife officials and hunters for years. But now it seems the disease could be more dangerous than previously thought. The Great Lakes Radio Consortium’s Christina Shockley reports:

Transcript

A disease that infects deer and elk has been alarming wildlife officials
and hunters for years, but now it seems the disease could be more
dangerous than previously thought. The Great Lakes Radio Consortium’s
Christina Shockley reports:


Chronic Wasting Disease, or CWD, affects the brain tissue of deer and
elk. Sponge-like holes form in the brains of sick animals. The deer
begin to waste away, become weak, and then die.


Since CWD was discovered in Colorado nearly forty years ago, wild deer
in nine other states have tested positive for the disease. Little is known
about CWD – including how to stop it.


What scientists do know is that the infectious proteins-called prions –
thought to cause CWD are found in the brain and spinal cord areas of
infected animals, but officials still don’t have the answer to the big
question.


Judd Aiken is a professor of Animal Health and Biomedical Sciences at
the University of Wisconsin.


“The ultimate question is whether venison from infected animals, CWD infected
deer, poses a risk to humans. Clearly the first question that needed to be
asked and addressed was whether there was infectivity in muscle.”


Recent findings say there is.


Researchers at the University of Kentucky injected muscle from an
infected deer into the brains of genetically altered mice. The mice
displayed signs of CWD. This is the first time the infectious proteins
blamed for CWD have been found in deer meat.


The finding raises questions about whether eating venison is safe.
Researchers including Aiken say the study is important, but has limits.
For example, he says it doesn’t replicate what would happen in real life.
Plus, he says it’s probably unlikely humans can even get CWD. He says
studies suggest it’s difficult for the disease to jump to other species. Still,
he urges caution. Hunters should get the meat tested before they eat deer
from an area where CWD has been found.


“I, in no way, can advocate the consumption of infected deer, and indeed,
I would suggest due to the limitations of the CW tests, I don’t advocate
the consumption of deer obtained from a CWD endemic area.”


Even if the test comes back negative, Aiken says a negative result isn’t
always accurate, and infected animals in the beginning stages of the
disease can look and act normal.


(Sound of sporting goods store)


John White is a deer hunter from Sheboygan, Wisconsin. He’s in the
hunting section of a nearby sporting goods store. White isn’t too
concerned about Chronic Wasting Disease.


“Not a whole lot of people are worried about it. I mean, when it first
came out, some people were a little leery about it and didn’t want to hunt
that year, but they kinda got over it. I’m not really worried about it being
in the meat at all, because by the time the test comes back I’ll probably
have the deer eaten already and then it’s already too late.”


State wildlife officials say… that’s not a good idea. They recommend that
if you hunt deer in areas where the disease has been found, get the deer
tested before eating it. That message hasn’t changed… since learning the
prions could be in the meat. Some argue… it should change.


John Stauber is with a government watchdog group in Wisconsin, and
is co-author of “Mad Cow USA: Could the Nightmare Happen Here?”
He says officials are keeping quiet about the risk of CWD so they don’t
lose revenue from hunting licenses.


A large portion of state conservation agency budgets are dependent on
fees from hunting licenses. He says all deer that die should be tested for
the disease. Stauber also says CWD is a major human health concern.


“The biggest risk might not be the people who would die from
eating venison, but rather, the people who would die from the
contamination of the blood supply. This is a problem that would unfold
not in days or months or years, but even over decades.”


Stauber says it’s just a matter of time before Chronic Wasting Disease
spreads to people… he says some might even have the disease already,
and not know it.


But researchers like Judd Aiken from the University of Wisconsin say
people shouldn’t over-react.


“People should be concerned, but I don’t want people to panic, either. If
you think you may have consumed venison from infected animals, I don’t
think it’s likely that you’ll ever develop a human prion disease.”


But, Aiken says there’s too much we don’t know about the disease, and
since studies can take years to complete, we might be in the dark for a
while longer.


For the GLRC, I’m Christina Shockley.

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