Chronic Wasting Disease and Potential Transmission to Humans

Figure. Chronic wasting disease among free-ranging deer and elk by county, United States.

Geographic Distribution of Chronic Wasting Disease

The geographic extent of CWD has changed dramatically since 1996 (2). Two largely independent and simultaneous epidemics, one in free-ranging deer and elk and another in the captive elk and deer industry, appear to represent the main framework for explaining the disease's current distribution (2). More extensive and coordinated surveillance has provided a clearer picture of its distribution over the last few years. Since 2000, the disease in free-ranging cervids has been increasingly identified outside of the original CWD-endemic areas of Colorado and Wyoming (Figure). The observed distribution seems to be related in part to natural movement of deer and elk and to commercial movement of infected animals to areas far from the disease-endemic zone. Considerable attention has been given to recent increases in the geographic spread of the disease, which in some areas is likely a result of increased surveillance rather than evidence of explosive geographic spread.

No single original event or source links all wasting disease foci documented to date. Given the disease's insidious nature and the apparent duration (at least several decades) of epidemics among captive and free-ranging cervids, gaps in knowledge about its spread and distribution are not surprising, particularly within the captive deer and elk industry. However, our current knowledge cannot explain some of the distinct foci of CWD among free-ranging animals (e.g., in New Mexico and Utah). Thus, unidentified risk factors may be contributing to the occurrence of CWD among free-ranging and captive cervid populations in some areas.

Back to the beginning of the article.......



Ermias D. Belay,* Ryan A. Maddox,* Elizabeth S. Williams,† Michael W. Miller,‡ Pierluigi Gambetti,§ and Lawrence B. Schonberger*
*Centers for Disease Control and Prevention, Atlanta, Georgia, USA; †University of Wyoming, Laramie, Wyoming, USA; ‡Colorado Division of Wildlife, Fort Collins, Colorado, USA; and §Case Western Reserve University, Cleveland, Ohio, USA

Suggested citation for this article: Belay ED, Maddox RA, Williams ES, Miller MW, Gambetti P, Schonberger LB. Chronic wasting disease and potential transmission to humans. Emerg Infect Dis [serial on the Internet]. 2004 Jun [date cited]. Available from: www.cdc.gov...


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Chronic wasting disease (CWD) of deer and elk is endemic in a tri-corner area of Colorado, Wyoming, and Nebraska, and new foci of CWD have been detected in other parts of the United States. Although detection in some areas may be related to increased surveillance, introduction of CWD due to translocation or natural migration of animals may account for some new foci of infection. Increasing spread of CWD has raised concerns about the potential for increasing human exposure to the CWD agent. The foodborne transmission of bovine spongiform encephalopathy to humans indicates that the species barrier may not completely protect humans from animal prion diseases. Conversion of human prion protein by CWD-associated prions has been demonstrated in an in vitro cell-free experiment, but limited investigations have not identified strong evidence for CWD transmission to humans. More epidemiologic and laboratory studies are needed to monitor the possibility of such transmissions.

Chronic wasting disease (CWD) is classified as a transmissible spongiform encephalopathy (TSE), or prion disease, along with other animal diseases, such as scrapie and bovine spongiform encephalopathy. The only known natural hosts for CWD are deer (Odocoileus species) and Rocky Mountain elk (Cervus elaphus nelsoni) (1,2). CWD and other TSEs are believed to be caused by a pathogenic effect on neurons of an abnormal isoform of a host-encoded glycoprotein, the prion protein. The pathogenic form of this protein appears to be devoid of nucleic acids and supports its own amplification in the host. TSEs in animals primarily occur by transmitting the etiologic agent within a species, either naturally or through domestic husbandry practices. In contrast, most such encephalopathies in humans occur as a sporadic disease with no identifiable source of infection or as a familial disease linked with mutations of the prion protein gene (3). A notable exception among the human TSEs is the variant form of Creutzfeldt-Jakob disease (vCJD), which is believed to have resulted from the foodborne transmission of bovine spongiform encephalopathy (BSE) to humans (4,5).

www.cdc.gov...

This is what the whitehouse and national media don't want you to know. It is "posted" on the CDC website, but few "citizens" read this..

Thats what hppens when you depopulate apex predators like wolves and human hunters. Dsease spreads unchecked among the prey populations.

Originally posted by mwm1331
Thats what hppens when you depopulate apex predators like wolves and human hunters. Dsease spreads unchecked among the prey populations.

OK, let me simplify........THIS IS MAD COW DISEASE in the deer and elk population in the US and has been transmitted to humans. The epicenter is near a major bio-research center........

OK, let me simplify........THIS IS MAD COW DISEASE in the deer and elk population in the US and has been transmitted to humans. The epicenter is near a major bio-research center........

This is getting worse by the moment, isn't it? The fact that it is near a bio-research center is a little disconcerting now isn't it? What is going on? Is the governing body actually partially to blame with this outbreak? I keep hearing about the Avian Flu, and how it's going to wipe out large amounts of people. However this prion related disease IMHO is far more dangerous, yet it is relatively unreported. Here a cow, there a cow, blah blah blah, but nothing of the relevance that I've learned here over the last little while. I've read that not only do cattle, goats, elk and deer, which are all mammals been diagnosed with the disease, but also fish as well.
Think about that for a moment. I've eaten almost every type of the animals which are diagnosed.
Now if a host has been infected with Prions, and the milk is then extracted from the host, and then drunk by humans. Is the human who drank the milk at risk of being infected? Are an entire generation of infants and children already doomed?
I pray not.

Originally posted by superdude
I've read that not only do cattle, goats, elk and deer, which are all mammals been diagnosed with the disease, but also fish as well.
Think about that for a moment. I've eaten almost every type of the animals which are diagnosed.

Wait? they've detected CWD in fish as well? Thats really scary do you have a link? So basically our entire meat chain is tainted with CWDs, whats the status on pork?

Now if a host has been infected with Prions, and the milk is then extracted from the host, and then drunk by humans. Is the human who drank the milk at risk of being infected? Are an entire generation of infants and children already doomed?
I pray not.

I thought prions were spread through the muscle tissue, not milk?

Yeah here is a link that gives some really great info - Thanx mostly to soficrow & DrHoracid.

www.abovetopsecret.com...

This is scary beyond anything I thought. This truly has the potential to be a modern day plague.

what bio-research center is near the outbreaks???


ok.........i'm confused..........when discussing mad cow the "EXPERTS" all said that it couldn't be passed to humans unless they consumed the meat,organs.........or pieces of the CNS(central nervous system)

NOW you say it can be passed through milk???

is that a definitive statement or a supposition??

angie

Originally posted by amb1063
what bio-research center is near the outbreaks???


ok.........i'm confused..........when discussing mad cow the "EXPERTS" all said that it couldn't be passed to humans unless they consumed the meat,organs.........or pieces of the CNS(central nervous system)

NOW you say it can be passed through milk???

is that a definitive statement or a supposition??

angie

Ok look at the "map" and check this out.

static.highbeam.com...

Originally posted by DrHoracid

Originally posted by amb1063
what bio-research center is near the outbreaks???


ok.........i'm confused..........when discussing mad cow the "EXPERTS" all said that it couldn't be passed to humans unless they consumed the meat,organs.........or pieces of the CNS(central nervous system)

NOW you say it can be passed through milk???

is that a definitive statement or a supposition??

angie

Ok look at the "map" and check this out.

static.highbeam.com...

DRHA..........appreciate the link.

thanks
angie

Another good one DrH.

Check this one out too, lots of good info and refs...

"Mad Cow" Spreading in Deer and Elk
www.abovetopsecret.com...


"Chronic wasting disease" in deer and elk
is caused by a specific infectious prion strain, related to "Mad Cow" disease. The Wyoming Game and Fish Department wants to start regulating the disposal of deer and elk carcasses. Chronic wasting disease is found in wild herds in Wyoming and Colorado, and also Nebraska, New Mexico, Illinois, South Dakota, Utah and Wisconsin. It has spread to domestic herds in Colorado, Montana and other states.

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