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I just read an article about the spread of CWD. I think a lot of people suspected this, it's just the first testing that has confirmed it. Here's the link to the article online:
http://www.rockymountainnews.com/drmn/state/article/0,1299,DRMN_21_2863940,00.html
Here's the article (clipped a little cuz it was pretty long):
CWD transmission test confirms gloomy view
By Gary Gerhardt, Rocky Mountain News
May 6, 2004
A one-year study has confirmed what has long been feared about how readily chronic wasting disease can spread without healthy animals ever coming in direct contact with infected ones.
It's long been suspected that the disorder could be transmitted indirectly to deer and elk through environmental contamination from urine or feces, or decomposed infected carcasses.
A joint study by Colorado and Wyoming researchers has confirmed that if healthy animals were placed in pens contaminated by infected carcasses, or allowed to graze grounds where there was excrement from infected animals, the disease could be contracted as well.
"We suspected animals could be infected if they ate grasses from the ground where animals with CWD had been, or if carcasses of animals that died of the disease that were left to decay could infect the environment as well," Williams said Wednesday.
To carry out the experiment, Williams said, a series of pens was constructed.
In one pen, healthy deer were exposed to infected deer. In a second pen, healthy deer were exposed to carcasses of deer that had died of CWD. And in the third, deer were simply confined in a pen where infected deer once had been kept.
The published research paper states: Under experimental conditions, mule deer became infected in two of three paddocks containing naturally infected deer, in two of three paddocks where infected deer carcasses had decomposed 1.8 years earlier, and in one of three paddocks where infected deer had last resided 2.2 years earlier.
Hobbs, of CSU's Natural Resource Ecology Laboratory in Fort Collins, said in a press statement that the research could be important in helping to slow the spread of CWD.
"Ultimately, we want to develop models that predict the behavior of the disease," Hobbs explained. "For example, we would like to predict how prevalence changes over time in different areas of Colorado."
Williams said a big question still unanswered is: In nature, what is the "half-life" of the prion, or misshapen protein, that is believed responsible for CWD, if it's left in the environment?
"We don't know if it is five years or 10 years or how long it is potent in nature," she said.
"It also should be pointed out that the experiment we just ran is a worst-case scenario because it was in a controlled situation. This isn't necessarily the way it will act in nature."
Hobbs reported that previous disease models have been based on animal-to-animal contact as the sole source of infection and that disease prevalence was expected to decline as the number of infected animals is reduced.
"Our findings that contaminated environments can cause transmission means that these declines in infection rates may be much slower than would be predicted by models that only consider animals-to-animal transmission," he said.
http://www.rockymountainnews.com/drmn/state/article/0,1299,DRMN_21_2863940,00.html
Here's the article (clipped a little cuz it was pretty long):
CWD transmission test confirms gloomy view
By Gary Gerhardt, Rocky Mountain News
May 6, 2004
A one-year study has confirmed what has long been feared about how readily chronic wasting disease can spread without healthy animals ever coming in direct contact with infected ones.
It's long been suspected that the disorder could be transmitted indirectly to deer and elk through environmental contamination from urine or feces, or decomposed infected carcasses.
A joint study by Colorado and Wyoming researchers has confirmed that if healthy animals were placed in pens contaminated by infected carcasses, or allowed to graze grounds where there was excrement from infected animals, the disease could be contracted as well.
"We suspected animals could be infected if they ate grasses from the ground where animals with CWD had been, or if carcasses of animals that died of the disease that were left to decay could infect the environment as well," Williams said Wednesday.
To carry out the experiment, Williams said, a series of pens was constructed.
In one pen, healthy deer were exposed to infected deer. In a second pen, healthy deer were exposed to carcasses of deer that had died of CWD. And in the third, deer were simply confined in a pen where infected deer once had been kept.
The published research paper states: Under experimental conditions, mule deer became infected in two of three paddocks containing naturally infected deer, in two of three paddocks where infected deer carcasses had decomposed 1.8 years earlier, and in one of three paddocks where infected deer had last resided 2.2 years earlier.
Hobbs, of CSU's Natural Resource Ecology Laboratory in Fort Collins, said in a press statement that the research could be important in helping to slow the spread of CWD.
"Ultimately, we want to develop models that predict the behavior of the disease," Hobbs explained. "For example, we would like to predict how prevalence changes over time in different areas of Colorado."
Williams said a big question still unanswered is: In nature, what is the "half-life" of the prion, or misshapen protein, that is believed responsible for CWD, if it's left in the environment?
"We don't know if it is five years or 10 years or how long it is potent in nature," she said.
"It also should be pointed out that the experiment we just ran is a worst-case scenario because it was in a controlled situation. This isn't necessarily the way it will act in nature."
Hobbs reported that previous disease models have been based on animal-to-animal contact as the sole source of infection and that disease prevalence was expected to decline as the number of infected animals is reduced.
"Our findings that contaminated environments can cause transmission means that these declines in infection rates may be much slower than would be predicted by models that only consider animals-to-animal transmission," he said.
