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Re: E-M:/ Michigan’s First Case of Chronic Wasting Disease Detected at Kent County



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Enviro-Mich message from "Larry D. =?utf-8?b?Tm9vZMOpbg==?=" <ldnum@umich.edu>
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I would also add a note about transmission; scrapie which is a prion disease affecting sheep is transmitted through saliva, and there is some evidence that this is also true for CWD in deer.

The Brits withheld information on mad cow disease from the Public in the early 1990s in order not to alarm the cattle industry, and look what it cost them in human and agricultural losses. Remeber that jumped to humans after much denial. Also, remember what happened when the MDA chose to deny and cover up the PBB problem instead of addressing it up front.

Eventually, I think the ban deer feeding and bait piles will also have to extend to salt licks. This catastrophe can be avoided by smart, decisive action.

To stave off denial, procrastination and cover ups on this important problem, here is some of the evidence:

Mathiason et al., Infectious prions in the saliva and blood of deer with chronic wasting disease. Science 314 (Oct 6): 133-6 (2006)

Abstract: A critical concern in the transmission of prion diseases, including chronic wasting disease (CWD) of cervids, is the potential presence of prions in body fluids. To address this issue directly, we exposed cohorts of CWD-naive deer to saliva, blood, or urine and feces from CWD-positive deer. We found infectious prions capable of transmitting CWD in saliva (by the oral route) and in blood (by transfusion). The results help to explain the facile transmission of CWD among cervids and prompt caution concerning contact with body fluids in prion infections.

And, there's more.


Quoting Chuck Cubbage <charles.cubbage@comcast.net>:


Jessica and Friends,

If I am not mistaken, there are strong associations between these types of diseases (prion caused central nervous system tissue damage) and the consumption infected brain or nervous system tissue. Hence the careful exclusion of feed containing brain tissue to sheep, cows, mink, and other livestock that are known to be susceptible.

Before going further, please be advised that I do not have any specific prion research expertise, but I have been exposed academically (since the 1960 - 70s) and later professionally while at MDA with the topic. I hope there are others with more up-to-date info to clarify points or correct any errors.

Go to : http://psyweb.com/Mdisord/Dementia/CJdisease.jsp for a discussion of the historical discovery of Creutzfeldt-Jakob Disease, one of the TSEs (transmissible spongeform encephalopathies). Cannibalism was part of the early recognition of a TSE with a 30 year incubation period.

I am going to presume that there is new information on some of the questions you raise since I participated in the Mad cow policy discussion in the 1990's while at MDA. However, based on information that was the best national research at that time, little was known about what "destroys" the "infectivity of TSEs (transmissible spongeform encephalopathies). The is group of diseases are caused by a class of protein.

The difficulty is that the incubation period differs from species to species (of animal infected) and is looong! In humans Creutzfeldt-Jakob Disease is a TSE - see http://www.cjdfoundation.org/cjdisease.html

The reference given by the State (see website in the original email (just add a third "w" to the address) focus on the deer/elk version of TSEs and do not attempt to tie the human version to the issue. It is interesting to note that in England, the human cases of TSE seemed to have significantly shortened incubation periods perhaps less than 5 years.

Also, see: http://en.wikipedia.org/wiki/Chronic_wasting_disease
I wonder if MDA has posted or could make electronically available the joint MDA-MSU evaluation of Mad-cow disease.


Regards,
Chuck
----- Original Message -----
From: Jessica Pociask
Cc: enviro-mich@great-lakes.net
Sent: Tuesday, August 26, 2008 11:31 PM
Subject: Re: E-M:/ Michigan’s First Case of Chronic Wasting Disease Detected at Kent County



Could anyone please elaborate on how this is typically spread, what risk it poses to humans, as well as if they know if the soil at these facilities where it has been detected can be burned to kill remaining pathogens.
Thank you.







On Aug 25, 2008, at 5:45 PM, HAMILTREEF@aol.com wrote:



FOR IMMEDIATE RELEASE Aug. 25, 2008

Contacts: Bridget Patrick (MDA) 517-241-2669 or Mary Dettloff (DNR) 517-335-3014

Michigan’s First Case of Chronic Wasting Disease Detected at Kent County Deer Breeding Facility

LANSING - The Michigan departments of Agriculture (MDA) and Natural Resources (DNR) today confirmed the state’s first case of Chronic Wasting Disease (CWD) in a three-year old white-tailed deer from a privately owned cervid (POC) facility in Kent County.

The state has quarantined all POC facilities, prohibiting the movement of all - dead or alive - privately-owned deer, elk or moose. Officials do not yet know how the deer may have contracted the disease. To date, there is no evidence that CWD presents a risk to humans.

DNR and MDA staff are currently reviewing records from the Kent County facility and five others to trace deer that have been purchased, sold or moved by the owners in the last five years for deer and the last seven
years for elk. Any deer that may have come in contact with the CWD-positive herd have been traced to their current location and those facilities have been quarantined.


“Michigan’s veterinarians and wildlife experts have been working throughout the weekend to complete their investigation,” said Don Koivisto, MDA director. “We take this disease very seriously, and are using every resource available to us to implement response measures and stop the spread of this disease.”

CWD is a fatal neurological disease that affects deer, elk and moose. Most cases of the disease have been in western states, but in the past several years, it has spread to some midwestern and eastern states.
Infected animals display abnormal behaviors, progressive weight loss and physical debilitation.


Current evidence suggests that the disease is transmitted through infectious, self-multiplying proteins (prions) contained in saliva and other fluids of infected animals. Susceptible animals can acquire CWD by
direct exposure to these fluids or also from contaminated environments. Once contaminated, research suggests that soil can remain a source of infection for long periods of time, making CWD a particularly difficult disease to eradicate.


Michigan’s First Case of Chronic Wasting Disease Detected at Kent County Deer Breeding Facility: page 2

“Currently, one of our top concerns is to confirm that the disease is not in free-ranging deer,” said DNR Director Rebecca Humphries. “We are asking hunters this fall to assist us by visiting check stations to
allow us to take biological samples from the deer they harvest, so we can perform adequate surveillance of the free-ranging white-tailed deer herd in the area.”


Deer hunters this fall who take deer from Tyrone, Soldon, Nelson, Sparta, Algoma, Courtland, Alpine, Plainfield, and Cannon townships will be required to bring their deer to a DNR check station. Deer taken in
these townships are subject to mandatory deer check.


The DNR is also asking hunters who are participating in the private land five-day antlerless hunt in September in other parts of Kent County to visit DNR check stations in Kent County so further biological samples can be taken from free-ranging deer for testing. The DNR is in the process of finding additional locations for check stations in Kent County to make it more convenient for hunters.

The deer that tested positive at the Kent County facility was a doe that had been recently culled by the owner of the facility. Michigan law requires sick deer or culled deer on a POC facility be tested for
disease. The samples from the Kent County deer tested “suspect positive” last week at Michigan State University Diagnostic Center for Population and Animal Health, and were sent to the National Veterinary
Services Laboratory in Ames, Iowa last Thursday for confirmatory testing. The positive results of those tests were communicated to the state of Michigan today.


Audits of the facility by the DNR in 2004 and 2007 showed no escapes of animals from the Kent County facility were reported by the owner. Also, there were no violations of regulations recorded during the audits.

Since 2002, the DNR has tested 248 wild deer in Kent County for CWD. In summer 2005, a number of those deer had displayed neurological symptoms similar to CWD; however, after testing it was determined the deer had contracted Eastern Equine Encephalitis.

More information on CWD is available on Michigan’s Emerging Diseases Web site at ww.michigan.gov/chronicwastingdisease.





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