Chronic Wasting Disease is no longer out of sight and mind for residents of America's fastest-growing micropolitan area with the announcement that a CWD-infected deer was confirmed in the Gallatin Valley just beyond Bozeman's back door. Photo by Todd Wilkinson
By Todd Wilkinson
Deadly, always-fatal and much feared Chronic Wasting Disease has now been confirmed in deer roaming both the Gallatin and Paradise valleys—and state wildlife officials are also concerned about a major emerging hotspot for disease along the lower Ruby River.
The arrival of CWD in big game animals around southwest Montana, a prominent part of the Greater Yellowstone Ecosystem, is certain to cause many to wonder how widespread the illness, which strikes members of the deer family (deer, elk, moose and caribou), might now actually be.
The fact that an infected white-tailed deer was killed by a hunter within sight of the suburbs of Bozeman is certain to elevate public concern to a whole new level.
During the first week of December, Montana Fish Wildlife
and Parks revealed that five new hunt areas had notched CWD positives for the
first time. Their locations are the Gallatin, Paradise and northern Madison
valleys east of the Tobacco Roots, as well as an area in the lower Missouri
Breaks near Wolf Point and a hunt unit in Beaverhead and Madison counties.
The revelation of greatest immediate worry, officials
say, is a cluster of CWD involving whitetails along the lower Ruby River near
Sheridan. There, Montana’s wildlife agency collected 335 tissue samples from
dead deer taken in Hunting District 322 and 78 of those, to date, have tested
positive. That’s a percentage far above
the norm.
To try to slow the infection rate, the state is carrying
out a supplemental post-season hunt to knock down whitetail numbers and get a
larger sampling size to better gauge CWD’s presence there. Reducing ungulate
numbers and preventing large concentrations of animals on winter ranges is part
of the state’s strategy for confronting the disease.
CWD was first confirmed in free-ranging big
game animals in the state in 2017 with a mule deer shot south of Billings not
far from Montana’s border with Wyoming. Since then, 343 tests from more than
16,000 samples have come back positive. The breakdown is 222 whitetails, 118
mule deer, one elk and two moose statewide.
However, the disease first raised alarm bells
earlier when it was detected in captive game farms in Montana in 1999 and again
this year. (Operating new game farms is forbidden in the state and those still
in existence were grandfathered following passage of a citizen initiative).
Montana’s
wildlife department spokesman Greg Lemon noted
that during 2004 and 2005 Montana made a serious attempt, using federal money,
to test harvested big game animals across the state but CWD then was never confirmed.
“We looked as hard as we could but didn’t find it,” he said. Wildlife vets
tested animals around Phillipsburg where game farm animals had escaped from
holding pens, but they too turned up negative.
Latest CWD prevalence map in Montana showing the disease has reached the four corners of the state. Experts say people should expect that it also exists everywhere in-between. While only recently confirmed in 2017, it seems to have spread quickly or has testing only confirmed what's been here for awhile. Graphic courtesy Montana FWP
All four deer-family species found in Wyoming
have also tested CWD positive with deer infections being far more prevalent
than elk. CWD arrived in Wyoming in mule deer in the southeastern corner of the
state in 1985 followed by a CWD-positive elk a year later. Since then it has fanned out in all
directions, putting it on collision course with the Greater Yellowstone Ecosystem—a region with
Yellowstone Park at its heart, known for having the most diverse and healthy concentrations
of big game animals in the Lower 48.
Idaho,
also a state that forms part of Greater Yellowstone, has so far not officially
confirmed any cases of CWD though experts say its arrival there too is
inevitable.
CWD originated in Colorado at a wildlife research lab in
the late 1960s and now is found in wildlife in more than two dozen states.
Classified as a “prion disease,” CWD is a cousin to notorious Mad Cow Disease
that decades ago infected cattle and people in the UK. More technically, CWD is
grouped among a category of prion illnesses known as transmissible spongiform ecephalopathies (TSEs), and it
shares company with bovine spongiform
encephalopathy (BSE) more commonly known as Mad Cow disease, scrapie in sheep, and
variant Creutzfeldt-Jakob disease (vCJD) in humans, and others.
Prions are not normal living pathogens like bacteria and
viruses but comprised of hardy misshapen proteins that attack the brain and
central nervous system of hosts, causing debilitating impacts similar to severe
dementia in humans. Afflicted animals in the final stages of life are often
thin and gaunt, staggering, foaming at the mouth and appear to have an
unquenchable thirst for water. A fair number, dazed and confused, are struck by cars.
A map prepared by the US Geological Survey, updated Dec. 1, 2020, showing the presence of CWD in the US and Canada in wild wildlife populations and animals at captive game farms. Soon, the disease is expected to reach Arizona, Nevada and the three states on the West Coast.
So far, there is no
confirmed case of CWD being transmitted to humans via people coming in contact
with diseased game animals or by eating them.
However, epidemiologist Dr. Michael Osterholm, whom
Mountain Journal has interviewed in the past and who is best known today for
his observation about Covid-19, believes animal to human transmission is
inevitable. He says it is only a matter of time, given differing emerging
strains of prions which continue to mutate and consumption of game meat by
large numbers of people, before the species barrier is crossed.
Osterholm during a conversation with Mountain Journal called attention to artificial feeding of wild elk in Wyoming as an example of how not to manage wildlife when CWD is moving through wild cervid populations, and he has also been critical of private captive game farms. The feeding that happens in Wyoming with public elk on public land, promoted and sanctioned by the state, represents the largest complex of artificial feeding of elk in the US and it has attracted national rebuke.
Recently in Jackson Hole at a webinar on CWD sponsored by
the Wyoming Game and Fish Department, state officials said they have no plans
to stop artificially feeding more than 20,000 elk that converge every winter on its state feedgrounds, many of which are found on lands managed by the US Forest
Service.
Apart from and by itself, the US Fish and Wildlife
Service’s National Elk Refuge, which begins at the northern boundary of the town
of Jackson, is home to between 7,000 and 8,000 wintering elk. Every major scientific
organization in the country associated with professional wildlife management
condemns the century-old practice of feeding wildlife because it bunches up
animals in large numbers where they become susceptible to catching and
transmitting diseases.
Thousands of elk congregate over artificial feed at the National Elk Refuge and 22 feedgrounds operated by the state of Wyoming every winter. Imagine if this were young human spring break goers in the time of Covid. Would such a convergence be considered wise amid the threat of a contagious disease? Epidemiologists say the same rules apply to wildlife when there's the looming menace of CWD and brucellosis. Photo courtesy Thomas Mangelsen (mangelsen.com)
A parallel of why congregating animals is a bad idea can
be found in the strategies for why public health officials advise against large
human gatherings in the face of the coronavirus pandemic. Notably, Montana and
Wyoming forbid the feeding of wildlife
by private citizens for the very reason that it elevates the risks of disease
transmission, not only for CWD, but brucellosis (which has been passed from elk
to cattle in Greater Yellowstone) as well as bovine tuberculosis, pneumonia, hoof and mouth disease
and others.
A large number of experts, including the former national
chief of animal health for the Fish and Wildlife Service, a veteran wildlife
scientist now retired from the Elk Refuge and several refuge managers have said
that CWD’s arrival in elk in Jackson Hole is imminent. Three years ago, a mule
deer that died literally on the edge of the Elk Refuge and Grand Teton National
Park tested positive for CWD.
In addition, more than a half dozen environmental groups
have filed lawsuits against the Fish and Wildlife Service and the Forest Service
for violating its governing laws that require its management actions to not
result in significant harm to resources under its charge.
The area in purple shows where CWD is present in Wyoming deer, elk and moose, some of which migrate hundreds of miles. Note the upper lefthand corner which has Yellowstone and Grand Teton national parks that represent places of convergence for vast herds, some of which might become infected with CWD if it reaches large wapiti concentrations on the National Elk Refuge. Graphic courtesy Wyoming Fish and Game
The
main reason for keeping the feedgrounds in operation is they help maintain an
artificially inflated population of elk desired by outfitters and guides who
sell hunts to paying clients.
Wyoming
wildlife officials and politicians have overtly resisted or opposed phasing out
artificial feeding at the 23 feedgrounds, based on unproved assertions that it
would cause a massive wapiti die-off, result in heightened disease threats for
cattle ranchers if elk dispersed more widely, and even asserting they do not
believe the CWD threat is as serious as claimed by scientists. Not lost is the irony that by concentrating
wildlife on public land, based on the rationale that they would help reduce the
risk of disease like brucellosis to cattle, they are actually creating graver
disease threats.
Despite
Wyoming for years minimizing CWD as a menace, mule deer herds in southeastern
Wyoming have suffered annual losses of more than 20 percent due to CWD. Just to
the south, in Colorado, the elk population in Rocky Mountain Park is dropping
markedly with CWD being a leading cause of death. Further, a research study done
in consultation with Wyoming’s state wildlife veterinarian predicts that after
CWD takes hold in elk, animals with the most common genetics could go extinct.
To date, no deer family member has demonstrated immunity to CWD and there is no
effective vaccine.
A research study done in consultation with Wyoming’s state wildlife veterinarian predicts that after CWD takes hold in elk, animals with the most common genetics could go extinct. To date, no deer family member has demonstrated immunity to CWD and there is no effective vaccine.
Some 20 years ago, three prominent officials
involved with wildlife and diseases in Wyoming warned about artificial feeding.
And, like warnings offered from federal and independent experts, they were ignored
by state biologists, members of the politically appointed Game and Fish
Commission and governors.
“Wildlife
have evolved
and adapted over millions of years to exist on
natural forage. A given
amount of habitat can only
support a given number of animals.
Often, we destroy habitat, which then
leads to
wildlife dying of starvation. Feeding allows us to
think we are compensating for habitat destruction when, in
fact, it makes a bad situation worse,” wrote Walter
Cook and Jim Logan, both state
veterinarians, and Scott Smith, a brucellosis biologist.
“We need to face the
fact that the only way to offset habitat destruction is via
habitat improvement. The evidence is undeniable. ‘Wildlife are adapted
to survive winter without supplemental feeding. Feeding causes
many more problems to wildlife than it solves.
Additionally, it can be harmful
to humans and domestic animals.”
Sixteen years later, Wyoming State Wildlife
Veterinarian Mary Wood stood before the Wyoming Game and Fish Commission and
said, “If we want to really look
at proactive management, the single most proactive thing we can do for
feedgrounds in the face of CWD is to find ways to reduce reliance on feed
before CWD ever hits.” She then noted, “We know that will occur. I would be
doing my profession and the oath that I took as a vet a disservice if I didn’t
say artificially concentrating animals over a feed source will facilitate
disease transmission.”
"We know that will occur. I would be doing my profession and the oath that I took as a vet a disservice if I didn’t say artificially concentrating animals over a feed source will facilitate disease transmission." —Dr. Mary Wood, appearing before the Wyoming Game and Fish Commission when she served as chief wildlife vet for the state.
Dr. Wood has since left
Wyoming and today is state veterinarian for Colorado Parks and Wildlife. Earlier in 2020, Colorado reported that CWD is
now present in 33 of 54 deer herds, 14 of 43 elk herds, and two of its nine
moose herds. The prevalence is rising in many of those populations. In 18 deer
herds, CWD prevalence exceeds five percent with a higher rate in mule deer than
whitetails.
History has shown that CWD rates of infection
often deepen over time and as they rise the cumulative year after year toll can
cause significant population declines. Six big game herds in Colorado have
prevalence rates in excess of 20 percent meaning at least one out of every five
adult males have the disease, are doomed to die and represent vectors for
passing it onto other herd members. Telling is that population declines commence when infection reaches 13 percent.
Given that in the Greater Yellowstone and
nearby surrounding states, there are many hundreds of thousands of deer and
elk, CWD striking animals in feedgrounds which then spreads more widely could
bring epic challenges.
A research elk in Wyoming afflicted with CWD and showing overt symptoms of the disease in its final days of life. Photo courtesy Wyoming Fish and Game
In response to growing
public pressure, Wyoming has tried to go on a PR offensive, announcing last
year that it was launching a new collaborative process of listening sessions
held across the state and sanguinely titled “Toward A Sustainable Future.”
Critics say Wyoming has more
than enough information than it will ever need to justify phasing out feeding
before a crisis arrives on the feedgrounds. And they assert that just as with
coal mining and politicians claiming it had a bright future as market
forces—namely the proliferation of cheap natural gas—caused its collapse,
leaders seem determined to buck the truth on CWD, too.
At Wyoming’s CWD webinar
last week, Game and Fish wildlife health laboratory supervisor Hank Edwards and Scott Edberg, the agency’s deputy chief
of wildlife, still, despite Wood’s earlier admissions, would not recommend phasing
out the feedgrounds even after hearing from prominent scientists over the years,
asserting that keeping them open could result in disaster.
In 2019, US Sen. John Barrasso of Wyoming sponsored a bill with his Democratic colleague, US Sen. Michael Bennett of Colorado, that would instruct the US departments of Agriculture and Interior in consultation with the well-respected National Academies of Sciences to develop "best management practices" and identify "the pathways and mechanisms for CWD transmission." It was endorsed by a number of sportsmans' groups and an organization called the Association for Fish and Wildlife Agencies.
"Wyoming’s deer, elk and moose populations have been negatively impacted by chronic wasting disease for decades,” Barrasso stated in a press release. "We need to know more about how this disease spreads and which areas are most at risk. Our bill gives wildlife managers the tools they need to research and identify exactly where chronic wasting disease is most prominent and how we can better prevent it."
One of the obvious culprits in his own state, the proverbial "elephant in the room," was right before Barrasso's eyes and he knew it: the feedgrounds, CWD watchdogs say. Within the professional wildlife establishment, there is no disagreement about this and no need for the government to spend money or draft legislation. One need only read the technical report on best practices for confronting CWD, spelled out in a benchmark report issued by the Association of Fish and Wildlife Agencies (AFWA)—of which Wyoming Game and Fish and the federal Fish and Wildlife Service are members. The AFWA itself signed on as a supporter of Barrasso's bill.
The title of the AFWA's document published half a year before Barrasso issued his press released and co-sponsored a bill? "Technical Report on Best Management Practices for Prevention, Surveillance, and Management of Chronic Wasting Disease." Apparently neither the senator nor his staff read it, for it identifies precisely what Barrasso claimed to be after.
"To reduce the risk of CWD transmission and establishment of CWD through unnatural concentrations of cervids, states and provinces should eliminate the baiting and feeding of all wild cervids using regulatory mechanisms such as jurisdictional bans," the contributors and reviewers of the AFWA report write.
They go on: "From the perspective of control and management of infectious diseases, anything that aggregates animals will, in most circumstances, also increase the opportunity for disease transmission. While natural aggregations of animals exist due to a variety of behavioral, seasonal, and resource factors, human-associated aggregations related to baiting and feeding can greatly increase the risk of disease transmission due to increased animal numbers and concentrations over extended time periods. This can lead to exposure to larger doses of infectious agents, multiple exposures, or exposures sustained over prolonged periods of time all resulting in greater probability of infection."
If that weren't enough, they knock down, without naming names, Wyoming's main arguments for keeping the feedgrounds open. "There is currently no evidence that baiting and feeding of free-ranging cervids can be conducted to mitigate increases in the opportunity for disease transmission. There is also no evidence the practice is likely to increase harvest sufficiently to overcome the negative effects of those increases by disease transmission."
What's noteworthy? Dr. Mary Wood, while still state vet for Wyoming, and Hank Edwards, Wyoming's current wildlife health laboratory supervisor, were part of the esteemed group that issued the paper. Edwards' own conclusions and those of his colleagues at Game and Fish today run counter to not only his professional peers beyond Wyoming who penned the AFWA report but the mountain of evidence they drew upon.
A report on best practices to combat CWD, released by the Association of Fish and Wildlife Agencies (and of which Wyoming is a member) states in no uncertain terms that artificially feeding wildlife runs counter to expert scientific opinion and mounds of evidence. Still, Wyoming chooses to defy what all other wildlife professionals say is the truth.
Retired Elk Refuge biologist
Bruce Smith, author of the critically-acclaim book Where Elk Roam has said CWD
reaching high infection rates in wintering elk, combined with the shedding of
prions into soils, could create a biological Superfund site. Pretending it
couldn’t happen, refusing to take bold action to prevent it from happening, he
said, is antithetical to the ethics and standards of professional wildlife management
in the 21st century.
Further, Dr. Tom Roffe, who oversaw animal
health for the whole of the Fish and Wildlife Service and has since retired to
a ranch in Montana, has told Mountain Journal in the past that Wyoming has for
decades stalled action it knows it needs to take and when given the option of
adhering to disease prevention practices embraced by the rest of the world, has
demonstrated its proclivity “for taking
every course of action possible except for the right, cautious one.”
Smith and Roffe, both lifelong avid hunters, say they will
no longer eat game animal meat from areas where they know the incidence of CWD
is established and rising. They also will be very wary of feeding game meat,
without knowing its source and origin, to their families for dinner. Both said it is not their intent to judge others. Calmly, Roffe said in an earlier interview, "Some may want to take the chance and believe it [animal to human transmission] will never happen. And good for them. But I'm one who thinks if I don't have to take the risk, then why do it?"
In the field, hunters are advised to wear gloves when
field dressing game in a CWD endemic area even if animals show no overt
symptoms of disease. Experts say that infected deer family members can remain
asymptomatic and spread CWD via saliva, urine, feces and via body
decomposition.
The
first CWD-infected deer confirmed in Montana appeared healthy when they were
taken by hunters. Notably, there are no reliable tests that can be given to
live animals to tell if they carry the disease; only after they are dead do
tests work.
Montana
Fish Wildlife and Parks spokesman Greg Lemon said that because CWD is known to
be a disease slow to move into a wildlife population and not as infectious as
other maladies, it is important to keep a calm head in pondering what its
presence means. He expects that as more test results come back, the number of
positive cases is certain to go up.
“We have numbers right now that are
a bit of a moving target,” Lemon said. “Batches of results are starting to come
in and there are quite a few samples still getting processed. We’re expecting
more positives to come through around the state. What’s clear is we have a hot
spot in the lower Ruby Valley involving whitetail deer.” He added there's also a higher-incidence of disease in deer in an area northeast of Dillon.
Lemon said the rising number of
confirmed cases appears to correlate to a rising number of test samples being
checked. While many have speculated that CWD’s arrival in southwest Montana may
be owed to the disease spreading from mixing with infected wildlife in Wyoming,
Lemon said surveillance and mapping actually show the disease is present
statewide.
CWD has been found in the northwest
corner of the state nearby Libby, in northern parts of Montana near the border
with the Canadian provinces of Alberta and Saskatchewan and in the east along
Montana’s border with North and South Dakota. “If people are hunting in Montana they should
assume it’s possible that CWD is present where they’re killing an animal to
have meat in the freezer,” he said. “The best way to have peace of mind is to
have the animals tested before you eat it”
Every year the
conservation groups Wyoming Wildlife Advocates and Sierra Club have produced
maps showing the progression of CWD in
the state. From 2001 to 2019, the
disease expanded in Wyoming elk hunt areas at an average rate of 762,000 acres
per year. The endemic area (where a disease is commonly found and present
within a particular place) for deer has expanded
around two million acres per year over
the same time, more than double the annual rate of expansion for elk.
Wyoming Game and
Fish announced a few months ago that CWD turned up in an infected elk near Cody
off the east side of Yellowstone Park but many believe it may already be
present in America’s first national park where every summer herds of elk and
mule deer converge from across the tri-state region.
How CWD might impact
wildlife in Yellowstone is not known but scientists say it will not be good. At
the same time, some biologists believe that healthy populations of Greater
Yellowstone’s “predator guild”—wolves, cougar, bears and coyotes—may be helping
to slow CWD as they kill prey that are weak and vulnerable from infection,
thereby preventing them from infecting others. Just as with humans, there has
not, as of yet, been a documented case of CWD afflicting predators.
The federal Centers for Disease
Control recommends that people should not eat game animals known to be infected
with CWD, as even cooking at high temperature does not kill prions.
In Montana and Wyoming presently there are no carcass transport restrictions, though in eastern states
it is illegal to move carcasses out of counties where CWD is known to exist. A
carcass may be moved anywhere in Montana regardless of where it was harvested
as long as the carcass parts are disposed of in a landfill after butchering /
processing. Carcass parts, such as brain, eyes, spleen, lymph glands, and
spinal cord material, should be bagged and disposed of in a landfill or may be
left at the kill site.
This
latter recommendation is itself somewhat controversial because prions are known
to be able to exist in the environment for years and have, under laboratory
conditions, been shown to be absorbed in the tissues of plants and persist in
soils.
One
major worry at the feedrounds in Wyoming is that CWD could create toxic zones
of environmental contamination leading to chronic infection of animals in a
certain area. The concern is not without reason. At a state research facility
in Wyoming, a study group of elk became sickened with CWD—and all died—after
being placed inside pens where CWD-infected animals early had been and were
gone.
Dr. Michael Osterholm Photo courtesy CIDRAP
Dr. Osterholm, who was
remarkably prescient in his predictions for how the Covid pandemic would play
out, was recently asked to serve on President-elect Joe Biden’s national public
health task force. Osterholm is a specialist in zoonotic diseases (diseases
that move between humans and animals) and he has been part of fact-finding
teams investigating Mad Cow and Ebola.
In 2018, as director of the Center for
Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota,
he made headlines by being publicly vocal about the consequences of CWD
spreading through wild deer in big hunting states like Minnesota, Wisconsin and
Michigan. He says that untold thousands of people in the US have consumed CWD-contaminated meat. The Alliance for Public Wildlife estimates that 7,000 to 15,000 CWD-infected animals are consumed annually, a number that may increase by 20 percent each year
While Osterholm says that
focusing on sources of potential accelerated spread should be a primary focus,
in addition to more federal investment in research and development of a
national strategy, he cautioned that should a human case of CWD be confirmed, a
major challenge will be containing hysteria.
Hunting, he says, is an
effective tool in culling animal herds and it helps maintain public support for
wildlife management agencies. Often herd reduction efforts focus on bucks and
bulls.
Osterholm cautioned that fear about disease, often fueled by misinformation,
can undermine public confidence in prudent management which is crucial in
confronting a frightening zoonotic disease like CWD.
Just because animal to
human transmission has not yet been confirmed, this does not mean it will not,
he said, noting the same assumption was made about cattle and people in Britain.
There remains a lot of unknowns about CWD, the same as there was about Mad Cow,
but the hard-won lessons of epidemiology do not go away simply because people,
for political decisions, claim they do not exist or apply to them.
Osterholm told Mountain Journal
that states need to pay more serious attention to the possibility of prions contaminating
the meat of healthy animals at processing plants and resulting in chronic contamination
on surfaces. And vigilance is required in monitoring deer and elk in captive facilities, where outbreaks have occurred in the US and Canada.
In a peer reviewed journal article published in mBio in 2019, Osterholm and four other authors wrote, "Available data indicate that the incidence of CWD in cervids is increasing and that the potential exists for transmission to humans and subsequent human disease. Given the long incubation period of prion-associated conditions, improving public health measures now to prevent human exposure to CWD prions and to further understand the potential risk to humans may reduce the likelihood of a BSE-like event in the years to come."
Surprising to some readers here is that in 2001 CWD was declared a national emergency yet as its reach has proliferated and states are having to do more with coordination of testing, management responses and hunter education, government investment in research and public health has not kept pace.
Titling their recommendation "a call to action," they write: "Despite the best efforts of wildlife agencies and other organizations to combat CWD, a unified approach has not been developed. A comprehensive strategy, with national leadership and support, is needed to address this important public health risk." They also call for mandatory national testing of big game animals so that a baseline can be established to make more informed decisions. And, yes, there is an economic interest at stake. "Without comprehensive, effective changes in wildlife management and the captive cervid industry, the nearly $40 billion annual contribution of wild cervid hunting in the United States is under threat," they say.
"Despite the best efforts of wildlife agencies and other organizations to combat CWD, a unified approach has not been developed. A comprehensive strategy, with national leadership and support, is needed to address this important public health risk."
While there remain a lot of what ifs—including whether crossing of the species barrier is biochemically possible—Osterholm says the possibilities increase when there is a convergence of risk factors. Prions continue to demonstrate an ability to mutate into new strains, more animals are getting infected, more land and more human surfaces could become prion contaminated, and more meat consumed. "Evidence...suggests that emerging CWD strains could have broader host ranges and higher zoonotic potential. A lack of assurance of an absolute species barrier necessitates a preventive public health approach."
This is what Wisconsin, which has been criticized for not being more vigilant earlier, now
advises: “CWD prions persist throughout
the body of an infected animal, even before the onset of clinical symptoms. While
handling and moving deer tissue, prions may bind to surfaces and remain
infectious for long periods of time. It is important to minimize the spread of
infectious material by properly cleaning work surfaces, equipment, and
clothing.”
The recommendation goes on
by saying that the following procedures should be followed to properly contain
and clean equipment exposed to CWD-infected tissues: “Line trash receptacles with non-porous,
single-use liners that can be sealed or enclosed. Minimize infectious material
in wastewater drains by removing and disposing of solids and other carcass
debris from work surfaces, equipment, and PPE (personal protective equipment,
the same equipment used during the Covid-19 pandemic). Pressure wash any
vehicles or equipment to be moved to and from areas of known CWD contamination.
Properly contain carcass waste in double-lined trash bags and dispose of in
acceptable landfill. Properly contain disposable clothing and equipment in
double-lined trash bags and dispose of in landfill. Thoroughly wash
non-disposable PPE prior to removal from contaminated site.”
As mentioned above, epidemiologists say surfaces
contaminated with prions can be difficult to disinfect. “Not only is it
important to clean all materials and surfaces that have been exposed to
potentially contaminated tissues of all organic solids, but also to use
additional methods to attempt to deactivate the disease agent prion. CWD prions
are unusually resistant to traditional chemical and physical disinfection and
sterilization methods. The most generally accepted method for complete
decontamination of prion infected material is incineration at 1800 degrees
Fahrenheit.”
The Wisconsin advisory, consistent with those
in other states, adds: “But because incineration is impractical for most
people, it is recommended that equipment and surfaces undergo disinfection by
soaking in a bleach water solution…Soak all appropriate processing equipment
and surfaces in a 50:50 bleach water solution for at least 1 hour. Rinse all
equipment and surfaces with clean, hot water after soaking in bleach water
solution.”
As with the controversies surrounding collective action for confronting Covid, there are segments of the general public that have demonstrated an obstinance in taking seriously precautions for CWD. Hunters in many states simply choose to eat meat and not get their game tested. Not long ago, it was reported that the Wisconsin Department of Health Services maintains a list of individuals who have consumed CWD-positive animals and nearly 1,000 people have agreed to participate in the state’s long-term disease surveillance program.
Accompanying the box of steaks, roasts, burger and salami home is also suspicion of how did your deer or elk get processed among all of the others? Merely mentioning the acronym CWD can cause indigestion.
One thing is certain, in many states gone are the carefree days when nothing but sublime sentiments were associated with the act of putting natural food on the table and choosing from an array of how venison or other game meat could appeal to the palate. Accompanying the box of steaks, roasts, burger and salami home is also suspicion of how did your deer or elk get processed among all of the others? Merely mentioning the acronym CWD can cause indigestion.
In Michigan, health officials advise that if
you are processing deer from a CWD core area or management zone, the waste,
inedible materials, spinal cord, brain tissue and other material should be
handled in a specific manner. “Waste created from the processing of the
carcass should be bagged and sent directly to a landfill. Do not render, burn,
compost or place in the environment parts from deer that potentially have Chronic
Wasting Disease as this could contaminate the environment or soil and spread
the disease.”
Specifically regarding the handling of game
meat, Michigan officials say: “Segregate any suspect venison from larger
comingled batches of sausages, snack sticks, etc., and do not process until the
test results come back negative.”
In their scientific paper in mBio, Osterholm and colleagues assert that faster, better diagnostic testing for CWD urgently needed and labs need to have improved capacity because hunters in many states have to wait weeks for results after they kill their game animal. "This delay is significant, since hunters might choose to process or consume the meat from cervids in the interim," they write. "This could lead to unrecognized and unnecessary exposure to CWD prions and contamination of meat-processing equipment, as prions have been shown to bind to metal without losing infectivity."
Somewhat worrisome, the authors pointed again to Wisconsin and highlighted why caution should be the watchword. "Despite the Wisconsin DNR offering CWD testing to hunters in surveillance areas at no cost, only 5 percent of Wisconsin’s 336,464 deer harvested in 2018 were tested. Furthermore, only 4,925 of the 23,441 deer harvested in four Wisconsin counties (Dane, Iowa, Richland, and Sauk) where CWD is most established were tested in 2018, with 894 (18 percent ) testing positive. More than 18,500 deer harvested in these four Wisconsin counties were not tested for CWD, suggesting that the meat from at least 3,000 CWD-positive animals was consumed, given the previously determined prevalence. Until gaps in CWD surveillance are addressed, the extent of CWD in cervid populations will remain unknown and people will unknowingly consume prion-infected meat."
Lemon of Montana Fish Wildlife and Parks told
Mountain Journal earlier this year that discussions have occurred on a number
of levels, stretching from hunters going afield to legislators and the governor,
about how prion containment regulations might be applied to commercial game
meat processors the same as the US Department of Agriculture regulates beef slaughterhouses.
Optimists would say there is good news relating to the December announcement that five new hunting districts in Montana have been added as areas where CWD is present. The upshot is that only single deer in the Gallatin, Paradise, and upper Madison valleys tested positive. But those are big dells and they are home to a lot of wildlife. Isolated solo cases of CWD are extremely rare and where there's one infected animal there's likely several more. With Paradise Valley, it reaches almost to the front doorstep of Yellowstone and every winter herds of hundreds of mule deer and elk can be seen along the flanks of the mountains north of Yankee Jim Canyon.
Until a lot more is known and a lot more test results come in, hunters and the public in Greater Yellowstone, when it comes to navigating the potentially perilous terrain of CWD, will be doing so in the dark.
About Todd Wilkinson
Todd Wilkinson, founder of Mountain Journal, is author of the book Ripple Effects: How to Save Yellowstone and American's Most Iconic Wildlife Ecosystem. Wilkinson has been writing about Greater Yellowstone for 35 years and is a correspondent to publications ranging from National Geographic to The Guardian. He is author of several books on topics as diverse as scientific whistleblowers and Ted Turner, and a book about the harrowing story of Jackson Hole grizzly mother 399, the most famous bear in the world which features photographs by Thomas Mangelsen. For more information on Wilkinson, click here. (Photo by David J Swift).
