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The Michigan DNR cites Chronic Wasting
Disease or CWD as a major concern for the Michigan White-tailed deer herd. While
the disease should be taken seriously it does not currently represent the threat
often portrayed by the DNR. It appears to me that CWD is being used as an excuse
to accumulate control and power over the deer that belong to the citizens of
Michigan not to the DNR. With a total of nine (9) case in the entire state and
none in Mason County this is not the threat that the DNR likes to make it out as
being to justify culls.
CWD is a progressive, fatal disease
that affects the brain, spinal cord, and many other tissues of farmed and
free-ranging deer, elk, and moose. CWD belongs to a family of diseases called
prion diseases or transmissible spongiform encephalopathies (TSEs). The
following information is from the CDC and can be read directly from their site
by going here.
Chronic wasting disease (CWD) is a prion
disease that affects deer, elk, reindeer, sika deer and moose. It has been found
in some areas of North America, including Canada and the United States, Norway
and South Korea. It may take over a year before an infected animal develops
symptoms, which can include drastic weight loss (wasting), stumbling,
listlessness and other neurologic symptoms. CWD can affect animals of all ages
and some infected animals may die without ever developing the disease. CWD is
fatal to animals and there are no treatments or vaccines.
To date, there have been no reported cases
of CWD infection in people. However, some animal studies suggest CWD poses a
risk to certain types of non-human primates, like monkeys, that eat meat from
CWD-infected animals or come in contact with brain or body fluids from infected
deer or elk. These studies raise concerns that there may also be a risk to
people. Since 1997, the World Health Organization has recommended that it is
important to keep the agents of all known prion diseases from entering the human
food chain.
Occurrence
As of June 2022, CWD in free-ranging deer, elk and/or moose has been reported in
at least 29 states in the continental United States, as well as two provinces in
Canada. In addition, CWD has been reported in reindeer and/or moose in Norway,
Finland and Sweden, and a small number of imported cases have been reported in
South Korea. The disease has also been found in farmed deer and elk.
CWD was first identified in captive deer
in a Colorado research facility in the late 1960s, and in wild deer in 1981. By
the 1990s, it had been reported in surrounding areas in northern Colorado and
southern Wyoming. Since 2000, the area known to be affected by CWD in
free-ranging animals has increased to at least 29 states, including states in
the Midwest, Southwest, and limited areas on the East Coast. It is possible that
CWD may also occur in other states without strong animal surveillance systems,
but that cases haven’t been detected yet. Once CWD is established in an area,
the risk can remain for a long time in the environment. The affected areas are
likely to continue to expand.
Nationwide, the overall occurrence of CWD
in free-ranging deer and elk is relatively low. However, in several locations
where the disease is established, infection rates may exceed 10 percent (1 in
10), and localized infection rates of more than 25 percent (1 in 4) have been
reported. The infection rates among some captive deer can be much higher, with a
rate of 79% (nearly 4 in 5) reported from at least one captive herd.
Chronic Wasting Disease Among Free-Ranging
Cervids by County, Michigan, June 2022
There have been a total of 9
cases in Michigan. The following counties have at least one.
Clinton
Dickinson
Eaton
Gratiot
Ingham
Ionia
Jackson
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Transmission
Scientists believe CWD proteins (prions) likely spread between animals through
body fluids like feces, saliva, blood, or urine, either through direct contact
or indirectly through environmental contamination of soil, food or water. Once
introduced into an area or farm, the CWD protein is contagious within deer and
elk populations and can spread quickly. Experts believe CWD prions can remain in
the environment for a long time, so other animals can contract CWD from the
environment even after an infected deer or elk has died.
The CWD prion has been shown to
experimentally infect squirrel monkeys, and also laboratory mice that carry some
human genes. An additional study begun in 2009 by Canadian and German
scientists, which has not yet been published in the scientific literature, is
evaluating whether CWD can be transmitted to macaques—a type of monkey that is
genetically closer to people than any other animal that has been infected with
CWD previously. On July 10, 2017, the scientists presented a summary of the
study’s progress (access the recorded presentationExternalexternal icon), in
which they showed that CWD was transmitted to monkeys that were fed infected
meat (muscle tissue) or brain tissue from CWD-infected deer and elk. Some of the
meat came from asymptomatic deer that had CWD (i.e., deer that appeared healthy
and had not begun to show signs of the illness yet). Meat from these
asymptomatic deer was also able to infect the monkeys with CWD. CWD was also
able to spread to macaques that had the infectious material placed directly into
their brains.
This study showed different results than a
previous study published in the Journal of Virologyexternal icon in 2018, which
had not shown successful transmission of CWD to macaques. The reasons for the
different experimental results are unknown. To date, there is no strong evidence
for the occurrence of CWD in people, and it is not known if people can get
infected with CWD prions. Nevertheless, these experimental studies raise the
concern that CWD may pose a risk to people and suggest that it is important to
prevent human exposures to CWD.
Additional studies are under way to
identify if any prion diseases could be occurring at a higher rate in people who
are at increased risk for contact with potentially CWD-infected deer or elk
meat. Because of the long time it takes before any symptoms of disease appear,
scientists expect the study to take many years before they will determine what
the risk, if any, of CWD is to people.
Prevention
If CWD could spread to people, it would most likely be through eating of
infected deer and elk. In a 2006-2007 CDC surveyexternal icon of U.S. residents,
nearly 20 percent of those surveyed said they had hunted deer or elk and more
than two-thirds said they had eaten venison or elk meat. However, to date, there
is no strong evidence for the occurrence of CWD in people, and it is not known
if people can get infected with CWD prions.
Hunters must consider many factors when
determining whether to eat meat from deer and elk harvested from areas with CWD,
including the level of risk they are willing to accept. Hunters harvesting wild
deer and elk from areas with reported CWD should check state wildlife and public
health guidance to see whether testing of animals is recommended or required in
a given state or region. In areas where CWD is known to be present, CDC
recommends that hunters strongly consider having those animals tested before
eating the meat.
Tests for CWD are monitoring tools that
some state wildlife officials use to look at the rates of CWD in certain animal
populations. Testing may not be available in every state, and states may use
these tests in different ways. A negative test result does not guarantee that an
individual animal is not infected with CWD, but it does make it considerably
less likely and may reduce your risk of exposure to CWD.
To be as safe as possible and decrease
their potential risk of exposure to CWD, hunters should take the following steps
when hunting in areas with CWD:
Do not shoot, handle or eat meat from deer
and elk that look sick or are acting strangely or are found dead (road-kill).
When field-dressing a deer:
Wear latex or rubber gloves when dressing the animal or handling the meat.
Minimize how much you handle the organs of the animal, particularly the brain or
spinal cord tissues.
Do not use household knives or other kitchen utensils for field dressing.
Check state wildlife and public health guidance to see whether testing of
animals is recommended or required. Recommendations vary by state, but
information about testing is available from many state wildlife agencies.
Strongly consider having the deer or elk tested for CWD before you eat the meat.
If you have your deer or elk commercially processed, consider asking that your
animal be processed individually to avoid mixing meat from multiple animals.
If your animal tests positive for CWD, do not eat meat from that animal.
The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service
regulates commercially farmed deer and elk. The agency operates a national CWD
herd certification programexternal icon. As part of the voluntary program,
states and individual herd owners agree to meet requirements meant to decrease
the risk of CWD in their herds. Privately owned herds that do not participate in
the herd certification program may be at increased risk for CWD.
If you want to research this subject
further the following links are a good place to start.
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