Minnesota, National Veterinary Services Laboratory in Ames, Iowa, has confirmed CWD case near Pine Island
Minnesota, National Veterinary Services Laboratory in Ames, Iowa, has confirmed CWD case near Pine Island
Managing Chronic Wasting Disease The National Veterinary Services Laboratory in Ames, Iowa, has confirmed that a deer harvested by a hunter in November 2010 near Pine Island in southeastern Minnesota had Chronic Wasting Disease (CWD), which is fatal to deer, elk and moose but not known to affect humans or cattle. The diagnosis, which was confirmed Jan. 25, marks the first time CWD has been found in Minnesota's wild deer herd.
The disease is a serious concern, not only because of the obvious harmful effects on cervid health, but also due to the negative impacts to landowners, hunters and businesses.
The DNR has been actively on the lookout for CWD since 2002, when the disease was first found in a domestic elk farm in central Minnesota. The agency has been conducting surveillance for the disease because an important management strategy is early detection.
Since 2002, the DNR has tested more than 32,000 hunter-harvested or road-killed deer, 60 elk and and 90 moose as part of its early CWD detection strategy. Until now, laboratory analysis had never found a wild deer "presumed positive" for CWD.
http://www.dnr.state.mn.us/mammals/deer/cwd/index.html
MINNESOTA HIGHLY SUSPECT CWD POSITIVE WILD DEER FOUND NEAR PINE ISLAND
Managing Chronic Wasting Disease
A preliminary screening test strongly indicates that a deer harvested by a hunter in November 2010 near Pine Island in southeast Minnesota had Chronic Wasting Disease (CWD), which is fatal to deer, elk and moose but not known to affect human health. If the National Veterinary Services Laboratory in Ames, Iowa, confirms the University of Minnesota's preliminary diagnosis this marks the first time CWD has been found in Minnesota's wild deer herd.
The disease is a serious concern, not only because of the obvious harmful effects on cervid health, but also due to the negative impacts to landowners, hunters and businesses.
The DNR has been actively on the lookout for CWD since 2002, when the disease was first found in a domestic elk farm in central Minnesota. The agency has been conducting surveillance for the disease because an important management strategy is early detection.
Since 2002, the DNR has tested more than 32,000 hunter-harvested or road-killed deer, 60 elk and and 90 moose as part of its early CWD detection strategy. Until now, laboratory analysis had never found a wild deer "presumed positive" for CWD.
snip...
The Minnesota Department of Natural Resources has learned that an adult female deer harvested during the 2010 hunting season will likely be diagnosed with Chronic Wasting Disease (CWD), a brain and nervous system disorder found in deer, elk and moose. This is disappointing news but the DNR is well prepared to address it.
The discovery occurred last week during laboratory analysis of more than 500 samples (lymph nodes) taken from hunter-harvested deer taken within a 20-mile radius of Pine Island in southeastern Minnesota. Initial screening of all samples has been completed and this is the only suspect. The DNR collects and evaluates lymph nodes because CWD can be detected through microscopic analysis.
Official confirmation of the disease requires further analysis by the National Veterinary Services Laboratory (NVSL) in Ames, Iowa. The following information answers many common questions.
What is the practical implication of this finding? If the preliminary finding is confirmed by NVSL, this will mark the first time CWD has been found in wild deer in Minnesota. Though the disease has been detected in Minnesota on four previous occasions since 2002, all of the instances involved ?captive cervids,? meaning domestic deer or elk confined to a fenced-in commercial operation.
How did the disease enter Minnesota's wild deer herd? At this point, no one knows. In fact, we may never know. What is known is that the 'presumed positive' deer was harvested about three miles southwest of a former domestic elk farm near Pine Island. The farm's elk herd was depopulated after a seven-year-old female elk tested positive for CWD in January 2008. Three additional elk were found to be infected with CWD during the depopulation effort. The closest wild deer with CWD in Wisconsin is 150 miles from the location this CWD-suspect deer was harvested in Minnesota.
What other states have CWD? CWD is found in wild deer, elk or moose in 13 other states and two Canadian provinces, including the Midwestern states of Wisconsin, Illinois, North Dakota and South Dakota. For specifics, visit the CWD Alliance Website.
What has DNR done to manage CWD? The DNR has done much to prevent CWD from entering Minnesota's wild deer herd. For many years the agency has worked closely with the Minnesota Board of Animal Health (the regulators of domestic deer and elk farms) on policies, procedures, and statutes to protect wild deer from coming into contact with commercially-raised elk and deer. The agency has also worked with the state Legislature to create animal transportation laws that minimize the risk of CWD from entering the state. For example, whole deer, elk, caribou or moose carcasses from other states or provinces may not be brought into Minnesota from areas known to have CWD in the wild.
The DNR has been actively on the lookout for CWD since 2002 when the disease was first found in a domestic elk farm in central Minnesota. The agency has been actively looking for the disease because an important management strategy is early detection. Since 2002, the DNR has tested more than 32,000 hunter-harvested or road-killed deer, 60 elk and and 90 moose in the name of early CWD detection. Until now, laboratory analysis had never found a wild deer "presumed positive" for CWD.
Was DNR specifically looking for CWD in the Pine Island area? Yes. It is a logical place to look because it's an area where CWD was recently discovered. The DNR collected 515 deer lymph node samples during the past deer season. This followed the collection of 934 deer from the same area in 2009. All of these deer were taken within a 25-mile radius of Pine Island. The DNR obtained these samples from hunters who voluntarily allowed DNR staff, University of Minnesota veterinary students and other experts to extract the lymph nodes at deer registration stations. In 2008, the DNR tested the lymph nodes of 500 hunter-harvested deer along the Wisconsin border from Houston County to St. Croix State Park. In 2009, the agency tested a total of 2,685 deer taken in southeastern Minnesota.
If CWD is confirmed, what will DNR do? DNR will implement its CWD response plan. The critical first step is to identify the number and current distribution of deer in the Pine Island area. This will be done using an aerial survey. Once DNR managers compile this data they will make plans to collect additional lymph nodes later this winter. Potential options for collecting these samples include a late winter deer hunting season, landowner shooting permits or sharp-shooting with permission of cooperating landowners. DNR will also implement a deer feeding ban in a CWD management zone surrounding the location of the positive animal, and restrict carcass movements out of the area.
Do you believe other deer in southeastern Minnesota have CWD?
A deer infected with CWD That's possible but it's premature to speculate. The only way to know if other deer have CWD is to continue doing surveillance. Collection of additional samples this winter will be done in a highly targeted way and only with permission of cooperating landowners.
If I harvested a deer from that area, should I be concerned about eating the venison? Based on the fact that only one deer has tested positive for CWD among more than 500 samples, the rate of occurrence is likely low. Still, people with venison in their freezer from this area should know the following:
The National Center for Disease Control (CDC) and the World Health Organization (WHO) have found no scientific evidence that CWD is transferrable from animals to humans; and The CDC advises against eating animals known to have CWD. So, people with venison in their freezer that was harvested from this area will need to make decisions based on the information above. The Minnesota Department of Health – not the DNR – provides guidance to citizens on food consumption issues.
What else can you tell me about CWD? CWD causes a characteristic spongy degeneration of the brains of infected animals resulting in emaciation, abnormal behavior, loss of bodily functions and death. CWD belongs to a group of diseases known as transmissible spongiform encephalopathies (TSEs). Though many observers try to compare CWD with "mad cow disease", the diseases are distinctly different.
What causes CWD? The disease agent is a prion, an abnormal form of cellular protein that is most commonly found in the central nervous system and in lymphoid tissue. The prion "infects" the host animal by promoting conversion of normal cellular protein to the abnormal form.
Where and how did CWD originate? The origin of CWD is unknown, and it may never be possible to definitively determine how or when CWD arose. It was first recognized as a syndrome in captive mule deer held in wildlife research facilities in Colorado in the late 1960s, but it was not identified as a TSE until the 1970s. Computer modeling suggests the disease may have been present in free-ranging populations of mule deer for more than 40 years.
How does CWD spread? It is not known exactly how CWD is transmitted. The infectious agent may be passed in feces, urine or saliva. Transmission is thought to be lateral (from animal to animal). Although maternal transmission (from mother to fetus) may occur, it appears to be relatively unimportant in maintaining epidemics.
Because CWD infectious agents are extremely resistant in the environment, transmission may be both direct and indirect. Concentrating deer and elk in captivity or by artificial feeding probably increases the likelihood of both direct and indirect transmission between individuals. Contaminated pastures appear to have served as sources of infection in some CWD epidemics. The apparent persistence of the infectious agents in contaminated environments represents a significant obstacle to eradication of CWD from either captive or free-ranging cervid populations.
The movement of live animals is one of the greatest risk factors in spreading the disease into new areas. Natural movements of wild deer and elk contribute to the spread of the disease, and human-aided transportation of both captive and wild animals greatly exacerbates this risk factor.
Why should Minnesotans be concerned about CWD? CWD poses serious problems for wildlife managers, and the implications for free-ranging deer, elk and moose are significant:
Ongoing surveillance programs are expensive and draw resources from other wildlife management needs; Impacts of CWD on population dynamics of deer and elk are presently unknown. Computer modeling suggests that CWD could substantially reduce infected cervid populations by lowering adult survival rates and destabilizing long-term population dynamics; Where it occurs, CWD may alter the management of wild deer and elk populations, and it has already begun to do so; and Ultimately, public and agency concerns and perceptions about human health risks associated with all TSE's may erode hunters' confidence and their willingness to hunt in areas where CWD occurs.
http://www.dnr.state.mn.us/mammals/deer/cwd/index.html
Friday, January 21, 2011
MINNESOTA HIGHLY SUSPECT CWD POSITIVE WILD DEER FOUND NEAR PINE ISLAND
http://chronic-wasting-disease.blogspot.com/2011/01/minnesota-highly-suspect-cwd-positive.html
Tuesday, January 25, 2011
Generation of a new form of human PrPSc in vitro by inter-species transmission from cervids prions
Marcelo A. Barria1, Glenn C. Telling2, Pierluigi Gambetti3, James A. Mastrianni4 and Claudio Soto1,*
1Mitchell Center for Alzheimer’s disease and related Brain disorders, Dept of Neurology, University of Texas Houston Medical School, Houston, TX 77030, USA
2Dept of Microbiology, Immunology & Molecular Genetics, and Neurology, Sanders Brown Center on Aging, University of Kentucky Medical Center, Lexington, KY, USA
3Institute of Pathology, Case Western Reserve University, Cleveland, OH, USA
4Dept of Neurology, University of Chicago, Chicago, IL, USA.
Running Title: Conversion of human PrPC by cervid PrPSc
Keywords: Prion / transmissible spongiform encephalopathy / infectivity / misfolded prion protein / prion strains
* To whom correspondence should be addressed. University of Texas Houston Medical School, 6431 Fannin St, Houston, TX 77030. Tel 713-5007086; Fax 713-5000667; E-mail Claudio.Soto@uth.tmc.edu
Prion diseases are infectious neurodegenerative disorders affecting humans and animals that result from the conversion of normal prion protein (PrPC) into the misfolded prion protein (PrPSc). Chronic wasting disease (CWD) is a prion disorder of increasing prevalence within the United States that affects a large population of wild and captive deer and elk. Determining the risk of transmission of CWD to humans is of utmost importance, considering that people can be infected by animal prions, resulting in new fatal diseases. To study the possibility that human PrPC can be converted into the misfolded form by CWD PrPSc we performed experiments using the Protein Misfolding Cyclic Amplification (PMCA) technique, which mimic in vitro the process of prion replication. Our results show that cervid PrPSc can induce the conversion of human PrPC, but only after the CWD prion strain has been stabilized by successive passages in vitro or in vivo. Interestingly, the newly generated human PrPSc exhibits a distinct biochemical pattern that differs from any of the currently known forms of human PrPSc. Our results also have profound implications for understanding the mechanisms of prion species barrier and indicate that the transmission barrier is a dynamic process that depend on the strain and moreover the degree of adaptation of the strain. If our findings are corroborated by infectivity assays, they will imply that CWD prions have the potential to infect humans, and that this ability depends on CWD strain adaptation.
snip...
Besides the importance of our results for public health in relation to the putative transmissibility of CWD to humans, our data also illustrate a very important and novel scientific concept related to the mechanism of prion transmission across species barriers. Today the view is that species barrier is mostly controlled by the degree of similarity on the sequence of the prion protein between the host and the infectious material (4). In our study we show that the strain and moreover the stabilization of the strain plays a major role in the inter-species transmission. In our system there is no change on the protein sequence, but yet strain adaptation results in a complete change on prion transmissibility with potentially dramatic consequences. Therefore, our findings lead to a new view of the species barrier that should not be seen as a static process, but rather a dynamic biological phenomenon that can change over time when prion strains mature and evolve. It remains to be investigated if other species barriers also change upon progressive strain adaptation of other prion forms (e.g. the sheep/human barrier).
Our results have far-reaching implications for human health, since they indicate that cervid PrPSc can trigger the conversion of human PrPC into PrPSc, suggesting that CWD might be infectious to humans. Interestingly our findings suggest that unstable strains from CWD affected animals might not be a problem for humans, but upon strain stabilization by successive passages in the wild, this disease might become progressively more transmissible to man.
please see full text and more here ;
Tuesday, January 25, 2011
Generation of a new form of human PrPSc in vitro by inter-species transmission from cervids prions
http://chronic-wasting-disease.blogspot.com/2011/01/generation-of-new-form-of-human-prpsc.html
http://chronic-wasting-disease.blogspot.com/
Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518
Managing Chronic Wasting Disease The National Veterinary Services Laboratory in Ames, Iowa, has confirmed that a deer harvested by a hunter in November 2010 near Pine Island in southeastern Minnesota had Chronic Wasting Disease (CWD), which is fatal to deer, elk and moose but not known to affect humans or cattle. The diagnosis, which was confirmed Jan. 25, marks the first time CWD has been found in Minnesota's wild deer herd.
The disease is a serious concern, not only because of the obvious harmful effects on cervid health, but also due to the negative impacts to landowners, hunters and businesses.
The DNR has been actively on the lookout for CWD since 2002, when the disease was first found in a domestic elk farm in central Minnesota. The agency has been conducting surveillance for the disease because an important management strategy is early detection.
Since 2002, the DNR has tested more than 32,000 hunter-harvested or road-killed deer, 60 elk and and 90 moose as part of its early CWD detection strategy. Until now, laboratory analysis had never found a wild deer "presumed positive" for CWD.
http://www.dnr.state.mn.us/mammals/deer/cwd/index.html
MINNESOTA HIGHLY SUSPECT CWD POSITIVE WILD DEER FOUND NEAR PINE ISLAND
Managing Chronic Wasting Disease
A preliminary screening test strongly indicates that a deer harvested by a hunter in November 2010 near Pine Island in southeast Minnesota had Chronic Wasting Disease (CWD), which is fatal to deer, elk and moose but not known to affect human health. If the National Veterinary Services Laboratory in Ames, Iowa, confirms the University of Minnesota's preliminary diagnosis this marks the first time CWD has been found in Minnesota's wild deer herd.
The disease is a serious concern, not only because of the obvious harmful effects on cervid health, but also due to the negative impacts to landowners, hunters and businesses.
The DNR has been actively on the lookout for CWD since 2002, when the disease was first found in a domestic elk farm in central Minnesota. The agency has been conducting surveillance for the disease because an important management strategy is early detection.
Since 2002, the DNR has tested more than 32,000 hunter-harvested or road-killed deer, 60 elk and and 90 moose as part of its early CWD detection strategy. Until now, laboratory analysis had never found a wild deer "presumed positive" for CWD.
snip...
The Minnesota Department of Natural Resources has learned that an adult female deer harvested during the 2010 hunting season will likely be diagnosed with Chronic Wasting Disease (CWD), a brain and nervous system disorder found in deer, elk and moose. This is disappointing news but the DNR is well prepared to address it.
The discovery occurred last week during laboratory analysis of more than 500 samples (lymph nodes) taken from hunter-harvested deer taken within a 20-mile radius of Pine Island in southeastern Minnesota. Initial screening of all samples has been completed and this is the only suspect. The DNR collects and evaluates lymph nodes because CWD can be detected through microscopic analysis.
Official confirmation of the disease requires further analysis by the National Veterinary Services Laboratory (NVSL) in Ames, Iowa. The following information answers many common questions.
What is the practical implication of this finding? If the preliminary finding is confirmed by NVSL, this will mark the first time CWD has been found in wild deer in Minnesota. Though the disease has been detected in Minnesota on four previous occasions since 2002, all of the instances involved ?captive cervids,? meaning domestic deer or elk confined to a fenced-in commercial operation.
How did the disease enter Minnesota's wild deer herd? At this point, no one knows. In fact, we may never know. What is known is that the 'presumed positive' deer was harvested about three miles southwest of a former domestic elk farm near Pine Island. The farm's elk herd was depopulated after a seven-year-old female elk tested positive for CWD in January 2008. Three additional elk were found to be infected with CWD during the depopulation effort. The closest wild deer with CWD in Wisconsin is 150 miles from the location this CWD-suspect deer was harvested in Minnesota.
What other states have CWD? CWD is found in wild deer, elk or moose in 13 other states and two Canadian provinces, including the Midwestern states of Wisconsin, Illinois, North Dakota and South Dakota. For specifics, visit the CWD Alliance Website.
What has DNR done to manage CWD? The DNR has done much to prevent CWD from entering Minnesota's wild deer herd. For many years the agency has worked closely with the Minnesota Board of Animal Health (the regulators of domestic deer and elk farms) on policies, procedures, and statutes to protect wild deer from coming into contact with commercially-raised elk and deer. The agency has also worked with the state Legislature to create animal transportation laws that minimize the risk of CWD from entering the state. For example, whole deer, elk, caribou or moose carcasses from other states or provinces may not be brought into Minnesota from areas known to have CWD in the wild.
The DNR has been actively on the lookout for CWD since 2002 when the disease was first found in a domestic elk farm in central Minnesota. The agency has been actively looking for the disease because an important management strategy is early detection. Since 2002, the DNR has tested more than 32,000 hunter-harvested or road-killed deer, 60 elk and and 90 moose in the name of early CWD detection. Until now, laboratory analysis had never found a wild deer "presumed positive" for CWD.
Was DNR specifically looking for CWD in the Pine Island area? Yes. It is a logical place to look because it's an area where CWD was recently discovered. The DNR collected 515 deer lymph node samples during the past deer season. This followed the collection of 934 deer from the same area in 2009. All of these deer were taken within a 25-mile radius of Pine Island. The DNR obtained these samples from hunters who voluntarily allowed DNR staff, University of Minnesota veterinary students and other experts to extract the lymph nodes at deer registration stations. In 2008, the DNR tested the lymph nodes of 500 hunter-harvested deer along the Wisconsin border from Houston County to St. Croix State Park. In 2009, the agency tested a total of 2,685 deer taken in southeastern Minnesota.
If CWD is confirmed, what will DNR do? DNR will implement its CWD response plan. The critical first step is to identify the number and current distribution of deer in the Pine Island area. This will be done using an aerial survey. Once DNR managers compile this data they will make plans to collect additional lymph nodes later this winter. Potential options for collecting these samples include a late winter deer hunting season, landowner shooting permits or sharp-shooting with permission of cooperating landowners. DNR will also implement a deer feeding ban in a CWD management zone surrounding the location of the positive animal, and restrict carcass movements out of the area.
Do you believe other deer in southeastern Minnesota have CWD?
A deer infected with CWD That's possible but it's premature to speculate. The only way to know if other deer have CWD is to continue doing surveillance. Collection of additional samples this winter will be done in a highly targeted way and only with permission of cooperating landowners.
If I harvested a deer from that area, should I be concerned about eating the venison? Based on the fact that only one deer has tested positive for CWD among more than 500 samples, the rate of occurrence is likely low. Still, people with venison in their freezer from this area should know the following:
The National Center for Disease Control (CDC) and the World Health Organization (WHO) have found no scientific evidence that CWD is transferrable from animals to humans; and The CDC advises against eating animals known to have CWD. So, people with venison in their freezer that was harvested from this area will need to make decisions based on the information above. The Minnesota Department of Health – not the DNR – provides guidance to citizens on food consumption issues.
What else can you tell me about CWD? CWD causes a characteristic spongy degeneration of the brains of infected animals resulting in emaciation, abnormal behavior, loss of bodily functions and death. CWD belongs to a group of diseases known as transmissible spongiform encephalopathies (TSEs). Though many observers try to compare CWD with "mad cow disease", the diseases are distinctly different.
What causes CWD? The disease agent is a prion, an abnormal form of cellular protein that is most commonly found in the central nervous system and in lymphoid tissue. The prion "infects" the host animal by promoting conversion of normal cellular protein to the abnormal form.
Where and how did CWD originate? The origin of CWD is unknown, and it may never be possible to definitively determine how or when CWD arose. It was first recognized as a syndrome in captive mule deer held in wildlife research facilities in Colorado in the late 1960s, but it was not identified as a TSE until the 1970s. Computer modeling suggests the disease may have been present in free-ranging populations of mule deer for more than 40 years.
How does CWD spread? It is not known exactly how CWD is transmitted. The infectious agent may be passed in feces, urine or saliva. Transmission is thought to be lateral (from animal to animal). Although maternal transmission (from mother to fetus) may occur, it appears to be relatively unimportant in maintaining epidemics.
Because CWD infectious agents are extremely resistant in the environment, transmission may be both direct and indirect. Concentrating deer and elk in captivity or by artificial feeding probably increases the likelihood of both direct and indirect transmission between individuals. Contaminated pastures appear to have served as sources of infection in some CWD epidemics. The apparent persistence of the infectious agents in contaminated environments represents a significant obstacle to eradication of CWD from either captive or free-ranging cervid populations.
The movement of live animals is one of the greatest risk factors in spreading the disease into new areas. Natural movements of wild deer and elk contribute to the spread of the disease, and human-aided transportation of both captive and wild animals greatly exacerbates this risk factor.
Why should Minnesotans be concerned about CWD? CWD poses serious problems for wildlife managers, and the implications for free-ranging deer, elk and moose are significant:
Ongoing surveillance programs are expensive and draw resources from other wildlife management needs; Impacts of CWD on population dynamics of deer and elk are presently unknown. Computer modeling suggests that CWD could substantially reduce infected cervid populations by lowering adult survival rates and destabilizing long-term population dynamics; Where it occurs, CWD may alter the management of wild deer and elk populations, and it has already begun to do so; and Ultimately, public and agency concerns and perceptions about human health risks associated with all TSE's may erode hunters' confidence and their willingness to hunt in areas where CWD occurs.
http://www.dnr.state.mn.us/mammals/deer/cwd/index.html
Friday, January 21, 2011
MINNESOTA HIGHLY SUSPECT CWD POSITIVE WILD DEER FOUND NEAR PINE ISLAND
http://chronic-wasting-disease.blogspot.com/2011/01/minnesota-highly-suspect-cwd-positive.html
Tuesday, January 25, 2011
Generation of a new form of human PrPSc in vitro by inter-species transmission from cervids prions
Marcelo A. Barria1, Glenn C. Telling2, Pierluigi Gambetti3, James A. Mastrianni4 and Claudio Soto1,*
1Mitchell Center for Alzheimer’s disease and related Brain disorders, Dept of Neurology, University of Texas Houston Medical School, Houston, TX 77030, USA
2Dept of Microbiology, Immunology & Molecular Genetics, and Neurology, Sanders Brown Center on Aging, University of Kentucky Medical Center, Lexington, KY, USA
3Institute of Pathology, Case Western Reserve University, Cleveland, OH, USA
4Dept of Neurology, University of Chicago, Chicago, IL, USA.
Running Title: Conversion of human PrPC by cervid PrPSc
Keywords: Prion / transmissible spongiform encephalopathy / infectivity / misfolded prion protein / prion strains
* To whom correspondence should be addressed. University of Texas Houston Medical School, 6431 Fannin St, Houston, TX 77030. Tel 713-5007086; Fax 713-5000667; E-mail Claudio.Soto@uth.tmc.edu
Prion diseases are infectious neurodegenerative disorders affecting humans and animals that result from the conversion of normal prion protein (PrPC) into the misfolded prion protein (PrPSc). Chronic wasting disease (CWD) is a prion disorder of increasing prevalence within the United States that affects a large population of wild and captive deer and elk. Determining the risk of transmission of CWD to humans is of utmost importance, considering that people can be infected by animal prions, resulting in new fatal diseases. To study the possibility that human PrPC can be converted into the misfolded form by CWD PrPSc we performed experiments using the Protein Misfolding Cyclic Amplification (PMCA) technique, which mimic in vitro the process of prion replication. Our results show that cervid PrPSc can induce the conversion of human PrPC, but only after the CWD prion strain has been stabilized by successive passages in vitro or in vivo. Interestingly, the newly generated human PrPSc exhibits a distinct biochemical pattern that differs from any of the currently known forms of human PrPSc. Our results also have profound implications for understanding the mechanisms of prion species barrier and indicate that the transmission barrier is a dynamic process that depend on the strain and moreover the degree of adaptation of the strain. If our findings are corroborated by infectivity assays, they will imply that CWD prions have the potential to infect humans, and that this ability depends on CWD strain adaptation.
snip...
Besides the importance of our results for public health in relation to the putative transmissibility of CWD to humans, our data also illustrate a very important and novel scientific concept related to the mechanism of prion transmission across species barriers. Today the view is that species barrier is mostly controlled by the degree of similarity on the sequence of the prion protein between the host and the infectious material (4). In our study we show that the strain and moreover the stabilization of the strain plays a major role in the inter-species transmission. In our system there is no change on the protein sequence, but yet strain adaptation results in a complete change on prion transmissibility with potentially dramatic consequences. Therefore, our findings lead to a new view of the species barrier that should not be seen as a static process, but rather a dynamic biological phenomenon that can change over time when prion strains mature and evolve. It remains to be investigated if other species barriers also change upon progressive strain adaptation of other prion forms (e.g. the sheep/human barrier).
Our results have far-reaching implications for human health, since they indicate that cervid PrPSc can trigger the conversion of human PrPC into PrPSc, suggesting that CWD might be infectious to humans. Interestingly our findings suggest that unstable strains from CWD affected animals might not be a problem for humans, but upon strain stabilization by successive passages in the wild, this disease might become progressively more transmissible to man.
please see full text and more here ;
Tuesday, January 25, 2011
Generation of a new form of human PrPSc in vitro by inter-species transmission from cervids prions
http://chronic-wasting-disease.blogspot.com/2011/01/generation-of-new-form-of-human-prpsc.html
http://chronic-wasting-disease.blogspot.com/
Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518
Labels: CONFIRMED Prion CJD, CWD, Minnesota
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