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Chronic Wasting Disease
Chronic wasting disease (CWD)
Chronic wasting disease (CWD) is a disease of the nervous system in deer and elk that results in distinctive brain lesions. It continues to be a major issue for wildlife scientists throughout the Nation.
New Approach May Detect Chronic Wasting Disease Earlier, at Less Cost, National Park Service, June 19, 2018The NPS and the U.S. Geological Survey collaborated with researchers from the Minnesota Department of Natural Resources, Princeton University and Wisconsin Department of Natural Resources on this innovative weighted sampling scheme. For this study, the scientists used previously collected data from deer in Wisconsin to develop precise but adaptable sampling protocols to guide tissue collection from deer in Shenandoah National Park in Virginia, where CWD is not known to occur.
Expert: Deer with CWD probably had disease most of her life, Leader Telegram, June 19, 2018A 2-year-old doe that died from chronic wasting disease in March in the town of Brunswick probably had the disease nearly all her life, a national CWD expert told heads of deer advisory committees Monday night at River Prairie Center. The incubation period for the disease is normally two years, although the symptoms of a “drooling, skinny” deer only show up during the last few weeks of the infection, said Bryan Richards of the National Wildlife Health Center in Madison.
Applying a Bayesian weighted surveillance approach to detect chronic wasting disease in white‐tailed deer, Journal of Applied Ecology, June 18, 2018Our approach allows managers to estimate relative surveillance weights for different host classes and quantify limits of disease detection in real time when only a sample of animals from a population can be tested, resulting in considerable cost savings for agencies performing wildlife disease detection surveillance. Additionally, it provides a rigorous means of estimating prevalence limits when a disease/pathogen is not detected in a sample set. It is therefore applicable to other wildlife, domestic animal and human disease systems, which can be characterized by surveillance classes with heterogeneous probability of infection.
Patrick Durkin: CWD continues to spread in Wisconsin , Wisconsin State Journal, April 28, 2018Two wild deer far outside Wisconsin’s endemic zone for chronic wasting disease tested positive last week for the always-fatal disease, and yet the Department of Natural Resources downplayed the news in press releases, emphasizing instead that the discoveries renewed baiting and feeding bans for the areas.The new CWD cases were reported April 18 in Eau Claire County and April 20 in Oneida County. Both were those counties’ first CWD cases in wild deer. The Eau Claire County case is 120 miles from Wisconsin’s most CWD-infected areas.
For the record, the agency documented a record 599 CWD cases during the 2017-18 surveillance year, which runs April through March. The DNR tested more deer last year (9,879) than in 2016-17, a 62 percent increase from 6,095, but still documented a 6 percent infection rate. The infection rate for 447 positives in 2016-17 was 7.3 percent.
Chronic Wasting Disease (CWD), CDC, April 18, 2018Nationwide, 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.
Wildlife Managers Want Public Input on Michigan’s Deadly Deer Disease, WDET, April 9, 2018“Some recent research has come out that this disease tends to accumulate exponentially in your deer herd. And once it does, there is an increase mortality rate with those animals. Even though they can live with it a lot longer than most diseases that they get, they still ultimately will succumb to it, it’s always fatal” -Chad Stewart, DNR
Chronic Wasting Disease: Coming to a Deer Population Near You, Sierra Club, March 11, 2018To control the disease, 32 states have implemented bans or restrictions on importing captive animals from areas with CWD, and 42 ban or restrict hunters from bringing in animal parts from other states, according to the Chronic Wasting Disease Alliance, a partnership of conservation groups. States also track the disease in wild herds by encouraging or requiring hunters to bring deer and elk to checkpoints for testing, and occasionally by sending in sharpshooters to kill deer in areas with CWD.
Study’s early data shows 75% of Wisconsin deer infected with CWD die in first year, Outdoor News, March 8, 2018During the winter of 2017, researchers put GPS collars on 138 deer. A total of 122 deer were successfully tested for CWD when captured and 12 deer tested positive for the disease at the time of capture. “The 12 CWD-positive deer is a small sample size, but we saw that, at the end of the year, three-fourths of those that were CWD-positive had died,” Storm said. In contrast to deer without CWD, at the end of the first year, three-fourths of those without CWD were still alive.
Deer: Researchers Sorting Out the Cause of Chronic Wasting Disease, Agfax, Feb 8, 2018When infected deer urinate, defecate, or salivate, they can shed prions. When a susceptible deer comes along and licks, ingests, or inhales infected soil it could pick up a prion. But soil is complex. It’s not clear what soil characteristics are associated with the persistence of chronic wasting disease in deer,” says Nohra Mateus-Pinilla, veterinary epidemiologist at the Illinois Natural History Survey-Prairie Research Institute. In the study, the team looked at the relationship between soil characteristics and presence of deer with the disease in five northern Illinois counties where infected deer are prevalent. They focused on seven physical and chemical properties of soil that could affect the ability for a prion to stick around in the environment.
Soil characteristics may be related to chronic wasting disease persistence, study finds, Science Daily, Feb 5, 2018In the study, the team looked at the relationship between soil characteristics and presence of deer with the disease [CWD] in five northern Illinois counties where infected deer are prevalent. They focused on seven physical and chemical properties of soil that could affect the ability for a prion to stick around in the environment. “The goal was to identify which soil characteristics have a greater effect on the persistent presence of chronic wasting disease in the five counties.”
* Deer tracking planned to help control deadly illness, Detroit Free Press, Jan 31, 2018Michigan State University and the Michigan Department of Natural Resources are working together on the project. The study will assess how deer movement and distribution patterns influence the spread of diseases in and around Clinton and Ingham counties.
2 deer in southwest North Dakota have wasting disease, Bismarck Tribune, Jan 31, 2018The North Dakota Game and Fish Department says two deer have tested positive for chronic wasting disease in the southwestern part of the state. A whitetail buck and a mule deer doe taken during the 2017 deer gun season from Unit 3F2 were found to have the deadly deer disease.
A Disease Turning Deer Into ‘Zombies’ Could Theoretically Spread to Humans, Men’s Health, Jan 22, 2018Frying it up or cooking it up on a high heat won’t kill it off. “The prion cannot be cooked or sanitized into oblivion. It requires either incineration or strong chemical dissolution (extreme alkaline pH or acidic pH),” says Perry Habecker, VMD, the chief of large animal pathology service, New Bolton Center, at the University of Pennsylvania School of Veterinary Medicine.
Panel wants stepped-up fight against deadly deer illness, Chronic Wasting Disease, Detroit Free Press, Jan 21, 2018LANSING — An advisory panel is calling for stepped-up efforts to prevent the spread of a deadly disease among Michigan deer.
Fifty-seven deer in six Lower Peninsula counties have tested positive for chronic wasting disease. The illness attacks the brain of infected animals. It’s transmitted through direct animal-to-animal contact, or by contact with their bodily fluids.
CWD Working Group provides deer management recommendations to Natural Resources Commission, Statewide DNR News, Jan 19, 2018Last fall the Natural Resources Commission and the Department of Natural Resources brought together CWD experts from around the country to review the latest in science and management principles on the disease. Other states have enacted policies that include changes in hunting regulations, restrictions or bans on deer carcasses from other states, baiting and feeding bans to prevent deer-to-deer contact that spreads the disease, bans on urine-based lures that are thought to spread the disease, and bans on live cervid movement from out of state.
51 deer found to have fatal disease as tests continue, ABC27, Jan 19, 2018HARRISBURG, Pa. (WHTM) – The Pennsylvania Game Commission says 51 deer from the 2017-18 hunting seasons have tested positive for chronic wasting disease so far. All positive tests were among deer harvested in disease management areas where the illness fatal to deer has been detected in captive and free-ranging deer.
Chronic Wasting Disease (CWD)- Occurance, CDC, Jan 16, 2018As of January 2018, CWD in free-ranging deer, elk and/or moose has been reported in at least 22 states in the continental United States, as well as two provinces in Canada. Since 2000, the area known to be affected by CWD in free-ranging animals has increased to at least 22 states, including states in the Midwest, Southwest, and limited areas on the East Coast. 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 have been reported.
Ohio confirms 1 case of disease fatal to deer, Fox8 Cleveland, Jan 14, 2018The Ohio Department of Agriculture says it has confirmed a positive case of chronic wasting disease in a captive deer and is taking steps to control any spread of the disease.
States Confront the Spread of a Deadly Disease in Deer, NYTimes, Jan 8, 2018[Chronic Wasting Disease] has ravaged deer herds throughout the United States and Canada and forced the killing of thousands of infected animals in 24 states and three Canadian provinces. It has also been found in Norway and South Korea. With the disease widespread in Wyoming, the Dakotas and the province of Alberta, Montana officials had been bracing for its emergence [in Montana].
Assessment of Chronic Wasting Disease Prion Shedding in Deer Saliva with Occupancy Modeling., J.Clinical Microbiology, Dec 2017Abstract. We were able to draw several conclusions pertinent to CWD biology from our analyses: (i) the shedding of prions in saliva increases with time postinoculation, but is common throughout the preclinical phase of disease; (ii) the shedding propensity is influenced neither by sex nor by prion protein genotype at codon 96; and (iii) the source of prion-containing inoculum used to infect deer affects the likelihood of prion shedding in saliva; oral inoculation of deer with CWD-positive saliva resulted in 2.77 times the likelihood of prion shedding in saliva compared to that from inoculation with CWD-positive brain. These results are pertinent to horizontal CWD transmission in wild cervids.
Suspected cases of chronic wasting disease in Michigan deer doubles, MLink, Dec 6, 2017As of Nov. 17, the Michigan Department of Natural Resources had identified 11 confirmed cases of the disease in deer since 2015, plus another three in which CWD was suspected. Less than a month later, that number has doubled. Thirty deer from Clinton, Ingham, Kent and Montcalm counties have been identified as positive cases of chronic wasting disease or “CWD suspect” cases since 2015. Michigan State University is working on testing several thousand additional samples, so numbers for this deer season could still change, according to the DNR.
DNR testing deer heads for chronic wasting disease as more are infected, Michigan Radio, Nov 29, 2017“There’s really no way to eradicate the disease, and that’s what the challenge is: Once you have it, you have it because of the environmental contamination component. So really what it amounts to is really focusing on some of those social groups that have it where we have known CWD-positive animals. We try to conduct very intensive management in those areas, so removing more deer than you typically would see from general hunting, and we try to supplement it that way. In the meantime, we’re doing surveillance in the surrounding areas. So we’re picking up roadkill deer, we’re having hunters submit deer for sampling, to constantly check what the boundaries of our known CWD area is in the state.”
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Why this deer disease could change the way Americans hunt forever, USA Today, Nov 27, 2017The deer that so far have tested positive for chronic wasting disease in Michigan are younger on average. And if allowed to grow, they would be shedding this indestructible disease in their feces, saliva and urine for that much longer.
Letting the disease spread is not an option. There’s increasing concern CWD, a prion disease similar to mad cow, eventually could cross the species barrier and spread to humans. Many scientists think it’s not a matter of if, but a matter of when. The Centers for Disease Control and Prevention warns not to eat the meat of contaminated deer. It’s possible CWD already has made the leap — comparable prion diseases have incubated for decades before dementia-like symptoms were recognized.
A fatal disease is spreading among U.S. deer, but there may be a new way to detect it, Popular Science, Nov 16, 2017The two existing USDA-approved CWD tests require brain and lymph node tissue, which is impossible to retrieve from a live deer. And testing for CWD before consumption is crucial. The disease has not yet been documented in humans, but the CDC advises against eating meat from infected animals. In July, Stefanie Czub, a scientists with the Canadian food inspection agency, presented evidence that macaque monkeys suffered from CWD after eating infected deer and elk. “It’s spreading in numbers, and geographically,” says Soto. “It’s an epidemic that is growing. And it’s dangerous because we don’t know if it can be transmitted to the human population.”
Confirmed deer with chronic wasting disease leads to well-attended meeting, MLink, Oct 26, 2017At the meeting, DNR wildlife veterinarian Dr. Kelly Straka and DNR deer specialist Chad Stewart, along with other DNR personnel, provided information on the disease, its effects on deer and deer populations, and how the DNR has responded to the discovery of the disease. Straka said that, to date, there has never been a human case of chronic wasting disease. However, it is an active area of study. As a precaution, the U.S. Centers for Disease Control and the World Health Organization recommend that infected animals not be consumed by either humans or domestic animals. Some deer can be sick for years without showing symptoms. CWD is transmitted through saliva and other bodily fluids of infected animals. There is no cure for the disease, and once an animal is infected it will eventually die. Federal lab confirms Montcalm County deer had chronic wasting disease, Statewide DNR News, Oct 6, 2017The animal, harvested in Montcalm Township in Montcalm County, is the 10th free-ranging deer in Michigan found to have chronic wasting disease. The youth hunter who harvested the deer opted to take the animal to a Department of Natural Resources deer check station and then submitted the animal for testing – steps the DNR strongly encourages hunters across the state to take during the 2017 deer hunting seasons.
Money, Power, and Deer Urine, New Yorker, Sept 25, 2017The plan’s disparate treatment of urine and meat is an example of what economists call regulatory capture: the process by which regulators, who are supposed to pursue solely the public interest, instead become solicitous of the very industries they regulate. Such industries typically use enormous amounts of money and political power to influence every detail of regulation.
2017 Deer Regulations Changes, Michigan Department of Natural Resources, Sept 11, 2017In the video above, the DNR’s Chad Stewart fills you in on some of the deer hunting regulation changes that are in effect this fall.
Concerns keep rising that chronic wasting disease could jump from deer to humans, Duluth News Tribune, July 14, 2017Amid renewed concern about whether chronic wasting disease can jump from deer to people, a fatal human brain condition in the same family is showing up more often in Wisconsin and nationally. It’s happening as state testing for the deer disease is down, and hunters routinely opt not to test deer killed in affected zones.
Diseased deer discovered in new spot in Pennsylvania, PennLive, July 13, 2017A free-ranging deer in Clearfield County has been confirmed as having chronic wasting disease, the Pennsylvania Game Commission revealed in announcing a news conference about the incident for noon today at the commission’s Harrisburg headquarters. The diseased buck was killed in an area of the state where CWD was detected previously, but only in deer in two captive deer enclosures.
Researchers Look To Fire To Combat Chronic Wasting Disease, WPR, July 5, 2017Neurological Condition Is Present In More Than Half Of Wisconsin Counties. Researchers have also found that CWD-infected animals also excrete prions through saliva, urine, and feces which can expose non-infected animals to the disease, said Zabel, and they can exist for a long time in various settings. The ease with which the disease can be transmitted and the longevity of prions led Zabel to consider how controlled fires could help to eradicate CWD.
Fire May Be the Only Remedy for a Plague Killing Deer and Elk, New York Times, June 26, 2017Once chronic wasting disease gets a foothold, it can spread relentlessly. It’s now documented in 24 states, and continues to expand into new ranges. In some herds, as many as half of the animals carry prions. It’s only been in recent years that scientists have gained crucial clues to how the disease spreads. Direct contact, it turns out, isn’t the only way that the prions get from one animal to another. Sick animals and cadavers spread prions across the landscape. Plants and soil may remain coated with deformed proteins for years, perhaps even decades. Dr. Zabel now suspects that the only way to rid the land of them is to set controlled fires.
Supreme Court rules law allows quarantine of CWD deer, not land, Radio Iowa, June 16, 2017The Iowa Supreme Court upheld the district court ruling — saying the law gives the DNR only the authority to quarantine the deer — not the land. The ruling says if the Iowa Legislature wants to expand the quarantine powers as suggested by the DNR, then it is free to do so.
2017 North American Deer Summit: CWD Is Worse Than We Thought, Realtree.com, June 9, 2017Several challenges arise with the big issue of CWD. First, we’re met with the challenge of detecting it. We don’t fully understand how it mutates (and science has proven that it can mutate). We have no cure. It’s killing deer throughout half the country and rapidly spreading. Managing it has been near to impossible. Too many people are brushing it under the rug. And funding we currently have for research, testing and management are pennies in comparison to what’s needed to defeat this disease.
The Ecology of Prions, Microbiology and Molecular Biolology Review, May 31, 2017Chronic wasting disease (CWD) affects cervids and is the only known prion disease readily transmitted among free-ranging wild animal populations in nature. The increasing spread and prevalence of CWD among cervid populations threaten the survival of deer and elk herds in North America, and potentially beyond. This review focuses on prion ecology, specifically that of CWD, and the current understanding of the role that the environment may play in disease propagation. We recount the discovery of CWD, discuss the role of the environment in indirect CWD transmission, and consider potentially relevant environmental reservoirs and vectors. We conclude by discussing how understanding the environmental persistence of CWD lends insight into transmission dynamics and potential management and mitigation strategies. (additional articles linked)
Can Michigan save deer from this deadly disease?, Lansing State Journal, May 25, 2017Unchecked, chronic wasting disease has the potential to wipe out half or more of Michigan’s deer herd in heavily infected areas, disrupting the state’s $2.3 billion hunting economy. That’s the worst-case scenario. It’s already playing out in Wyoming, one of the first states to discover the disease in wild deer. A 2015 study projected that it could cause extinction of the Wyoming mule deer herd within 41 years.
Elk and deer herds in danger decades after disease discovery, Billings Gazette, May 17, 2017After decades of work, wildlife managers are, in some ways, starting over in figuring out how to manage the disease. The Centers for Disease Control and Prevention still don’t recommend humans eat an infected animal, but there have been no cases of transmission. Nor did the disease initially tear through herds as quickly as first predicted. But that’s all starting to change. New models are showing that in the long term, mule deer numbers, particularly in central Wyoming, could plummet. Instead of raging through like an ancient plague, the disease kills slowly, taking years or even a decade, and spreading in ways no one quite understands. So Wyoming wildlife managers and researchers are regrouping, working at ground zero with new information and seeking input from the public as they race to grasp the full impact of — and possible solution to — one of the most deadly wildlife diseases facing the state.
25 wild deer test positive for chronic wasting disease, 27News.com, May 15, 2017 The Pennsylvania Game Commission says 25 wild deer have tested positive for chronic wasting disease in an area of the state where other wild deer have been found to have the fatal disease since 2012.
Study Shows How Chronic Wasting Disease Spreads in Wisconsin, USNews, April 21, 2017The disease has been found in more than 40 of Wisconsin’s 72 counties since the first confirmed cases in 2002. Richgels said it remains a threat throughout Wisconsin and that hunters should consider having their deer tested for the disease.
Chronic Wasting Disease, Texas A&M, April 11, 2017
Showcasing the DNR: Task force working on CWD prevention efforts in UP, DNR, March 2, 2017With the potential threat of chronic wasting disease spreading to the Upper Peninsula from across the Wisconsin border, or by other means, the Michigan Department of Natural Resources, hunter groups and others are working cooperatively to try to protect the region’s deer population and valuable hunting tradition. Previous studies showed CWD prions (infectious agents made from protein material) exist in the saliva, urine, blood and feces of infected animals.
Molecular Mechanisms of Chronic Wasting Disease Prion Propagation [abstract], Perspectives in Medicine, Feb 13, 2017The etiology of chronic wasting disease (CWD), a relatively new and burgeoning prion epidemic in deer, elk, and moose (members of the cervid family), is more enigmatic. The disease was first described in captive and later in wild mule deer and subsequently in free-ranging as well as captive Rocky Mountain elk, white-tailed deer, and most recently moose. It is therefore the only recognized prion disorder of both wild and captive animals. In addition to its expanding range of hosts, CWD continues to spread to new geographical areas, including recent cases in Norway. The unparalleled efficiency of the contagious transmission of the disease combined with high densities of deer in certain areas of North America complicates strategies for controlling CWD and raises concerns about its potential spread to new species. State says Mecosta County deer cull could begin by end of the week, MLive, Feb 2, 2017The Michigan Department of Natural Resources could test the remains of as many as 3,000 deer within a nine-township area over the next year after two farm-raised deer in Mecosta County tested positive for Chronic Wasting Disease (CWD) last month. The plan includes deploying sharpshooters to cull some deer in specific spots where CWD-positive deer were found.
Chronic wasting turns up in another SE Minnesota deer, MPR News, Jan 23, 2017The latest case was an adult female, killed near Preston, Minn., very close to where four other infected animals discovered, the Minnesota Department of Natural Resources said Monday. It brought to six the number of wild deer testing positive in southeastern Minnesota. Results are still pending on more than 100 samples.
Chronic Wasting Disease found at Mecosta County deer farm, Lansing State Journal, Jan 20, 2017The discovery of chronic wasting disease at a Mecosta County deer farm means state wildlife officials now have to fight the fatal disorder on two fronts. Nine wild deer killed in Ingham and Clinton counties have tested positive for the disease, the DNR said. The mandatory testing zone now includes 17 townships in Clinton, Eaton, Ingham and Shiawassee counties.
The deer farm where the infected animals lived will be quarantined and depopulated, state officials said. There also will be testing, fence inspections and audits of all deer farms within a 15-mile radius, as well as testing of free-ranging deer in the area.
2 More Deer Found With CWD, 5 County Feeding Ban In Place, CBS Local.com, Jan 10, 2017Wildlife managers have found two more deer suspected of being infected with chronic wasting disease near the southeastern Minnesota town of Preston, raising the number of confirmed and presumptive infected deer found in the area to five. The does were killed within a mile of where the first two deer that tested positive were shot in November, marking the first appearance of the brain disease in wild deer in Minnesota since 2010. The Department of Natural Resources expects confirmation later this week.
Third CWD-infected deer found in SE MN; special hunt starts Saturday, Kare11News, Dec 28, 2016Tuesday, the Minnesota Department of Natural Resources announced that a third deer was found infected with CWD. A hunter harvested the deer in mid-November. Around that same time, two other deer were killed that later tested positive for CWD about 4 miles west of Lanesboro. The third deer was killed about 5 miles north of the other two in southeastern Minnesota.
Video: Testing Deer for CWD, MDNR, Nov 10, 2016Have you ever wondered how deer are tested for Chronic Wasting Disease (CWD)? This short video walks you through the process.
Michigan continues to battle chronic wasting disease, MDNR, Nov 3, 2016Cases of disease fatal to white-tailed deer located in south central Michigan. The discovery of an eighth free-ranging Michigan white-tailed deer with chronic wasting disease this summer was a disappointment to Michigan Department of Natural Resources wildlife officials.
Suspect deer for chronic wasting disease identified in Ingham County, Statewide DNR News, Sept 12, 2016 3.5-year-old buck taken recently in Meridian Township is likely to be the eighth positive and the first discovered since March of this year. The sample is currently being tested by the U.S. Department of Agriculture’s National Veterinary Services Laboratory in Ames, Iowa, to finalize confirmation. “This latest suspect positive reinforces the notion that the disease is still occurring in Meridian Township and perhaps elsewhere,” said Chad Stewart, DNR deer specialist. “We are counting on hunters to bring their deer in for testing so we have a better understanding about the scope of the disease.”
Court says Missouri can’t ban deer imports over fears of disease, LakeExpo.com, Sept 17, 2016A state judge ruled this week against a ban on importing deer from other states to Missouri, a rule the state Department of Conservation had tried to impose to keep chronic wasting disease in check. The judge said that rules already in place by the Missouri Department of Agriculture go far enough to keep tabs on the risk of chronic wasting disease. His order said the Missouri Department of Conservation’s attempt to lock out deer from other states poses too great a danger to the captive deer industry and its ability to offer customers the trophy bucks they seek.
Researchers document first-ever evidence of white-tailed deer declines from CWD, Phys.org, Sept 2, 2016The research, led by recent UW Ph.D. graduate David Edmunds, under the direction of Associate Professor Todd Cornish in the Department of Veterinary Sciences, is the first conclusive evidence that CWD found at high prevalence leads directly to population declines in free-ranging deer populations. “The decline was caused directly by CWD lowering annual survival of female deer, which have the biggest impact on population growth rates,” Edmunds says. “This was because CWD-positive deer died both directly from the disease and were more likely to be killed by hunters than CWD-negative deer.”
Chronic Wasting Disease in White-tailed Deer: Infection, Mortality, and Implications for Heterogeneous Transmission, Ecology, July 2016We used epidemiological models to estimate the force-of-infection and disease-associated mortality for white-tailed deer in the Wisconsin and Illinois CWD outbreaks. Models were based on age-prevalence data corrected for bias in aging deer using the tooth wear and replacement method. Both male and female deer in the Illinois outbreak had higher corrected age-specific prevalence with slightly higher female infection than deer in the Wisconsin outbreak. Corrected ages produced more complex models with different infection and mortality parameters than those based on apparent prevalence. We found that adult male deer have > 3 fold higher risk of CWD infection than female deer. Males also had higher disease mortality than female deer. As a result CWD prevalence was 2 fold higher in adult males than females. We also evaluated the potential impacts of alternative contact structures on transmission dynamics in Wisconsin deer. Results suggested that transmission of CWD among male deer during the nonbreeding season may be a potential mechanism for producing higher rates of infection and prevalence characteristically found in males.
Southwest Colorado gets first deer infected with wasting disease, The Journal, July 12, 2016Colorado Parks and Wildlife says that it has found a deer that was infected with chronic wasting disease just east of Montrose, the first time that an infected deer has been found in Southwestern Colorado, a state Parks and Wildlife official said on Tuesday.
Fatal deer disease impacts Ionia County, Sentinel Standard, July 5, 2016Ionia County was placed in the deer chronic wasting disease management zone Tuesday by the Michigan Department of Natural Resources. Department of Natural Resources deer specialist Chad Stewart said seven deer in Michigan have tested positive for CWD. However, no deer found in Ionia County have tested positive for the disease. The reason for the expanded management zone is because three of the diseased deer were found in south Clinton County, which neighbors Ionia County.
Female deer disperse farther than males, present disease-control challenge, Science Daily, June 28, 2016“Dispersal of female deer is density dependent, meaning that higher deer densities lead to greater dispersal rates.” He explained. “Therefore, reducing deer density will reduce female dispersal rates — and likely will reduce disease spread. Containing the spread of chronic wasting disease is going to be difficult when female deer disperse.
Illinois is shining star in fight against deer disease, rrstar.com, June 19, 2016Laroche said targeted removal might be more effective than issuing permits to let hunters kill more deer in areas where the disease has been found. Another idea, which he admitted might sound strange, is to fence land to prevent diseased deer from migrating. Wisconsin hasn’t used targeted removal and the disease is more prevalent there than in Illinois, although the outbreaks in both states began in 2002.icials are revisiting that plan.
TPWD merits support in fight against chronic wasting disease, MySA.com, June 19, 2016The fairest way to deal with the threat of chronic wasting disease is not to expose the rest of the state’s wild deer herd to this fatal disease, but instead to take all necessary steps to control and limit the spread before it is too late.
Pa. Game Commission looks into targeted removal for diseased deer, Citizen’s Voice, June 7, 2016 The method called targeted removal seems to keep the prevalence of chronic wasting disease to around 1 percent in Illinois, Wayne Laroche, the director of wildlife management, told the commissioners during their working group meeting in Harrisburg on Monday. Laroche said targeted removal might be more effective than issuing permits to let hunters kill more deer in areas where the disease has been found. Another idea, which he admitted might sound strange, is to fence land to prevent diseased deer from migrating. Wisconsin hasn’t used targeted removal and the disease is more prevalent there than in Illinois, although the outbreaks in both states began in 2002.
AGFC Needs Hunters To Hunt To Manage Spread Of Deadly Deer Disease, KFSM, May 26, 2016“We need those hunters to go out there and harvest those deer,” Stephens said. “We need to get the deer densities down. We need to spread it out so that those deer are not infecting other deer when they are so close together. We really need the public’s help, especially hunters.”
Michigan expands deer chronic wasting disease test zone, Detroit Free Press, May 20, 2016The area has been enlarged from nine townships to 17 in Clinton, Eaton, Ingham and Shiawassee counties. Successful hunters in the area will be required to take their deer to a DNR check station for testing.
Decision time nears for CWD outbreak in wild Pennsylvania deer, Outdoor Newd, May 16, 2016The Wisconsin Department of Natural Resources in 2010 ended its effort to thin the deer herd in infected areas after growing public backlash. The agency’s plan since then has been to only monitor the disease with no attempts to control its spread. But now that strategy appears on the verge of costing Wisconsin’s economy billions of dollars. The Wisconsin whitetail population is being decimated by CWD – and it is now spreading even more quickly.
Seven new cases of chronic wasting disease found in Missouri deer, KY3.com, April 23, 2016The Missouri Department of Conservation (MDC) received final results from its 2015‐2016 fall and winter testing of nearly 7,700 free‐ranging deer for Chronic Wasting Disease (CWD). Seven were confirmed to be positive for the fatal deer‐disease. The new cases bring the total number of Missouri free‐ranging deer that have tested positive for CWD to 33 since the disease was first discovered in the state in 2010.
A contagious brain disease has hit Norway’s reindeer, and scientists are afraid of it spreading, Quartz, April 23, 2016What’s more baffling is that nobody knows how the disease got there. CWD was thought to be restricted to deer, elk, and moose in the US and South Korea. Though it’s theoretically possible that it jumped from another species in Norway (such as cows) to the reindeer, there are no previous known cases of that happening. The other possibility is that it just arose spontaneously—a protein misfolding into a prion by pure chance.
Wisconsin loses ground against fatal deer disease, Daily News, April 22, 2016The DNR tried to aggressively kill off deer after CWD was discovered near Mount Horeb in 2002, employing sharpshooters and asking hunters to kill as many deer as possible. The tactic devolved into a public relations nightmare: Hunters and landowners refused to get on board, calling herd reduction unattainable and a waste of deer.
Deadly animal prion disease appears in Europe, Nature, April 18, 2016A highly contagious and deadly animal brain disorder has been detected in Europe for the first time. Scientists are now warning that the single case found in a wild reindeer might represent an unrecognized, widespread infection. Chronic wasting disease (CWD) was thought to be restricted to deer, elk (Cervus canadensis) and moose (Alces alces) in North America and South Korea, but on 4 April researchers announced that the disease had been discovered in a free-ranging reindeer (Rangifer tarandus tarandus) in Norway. This is both the first time that CWD has been found in Europe and the first time that it has been found in this species in the wild anywhere in the world.
The first detection of Chronic Wasting Disease (CWD) in Europe, CWD-Info.org, April 5, 2016The Norwegian Veterinary Institute has diagnosed Chronic Wasting Disease (CWD) in a free-ranging reindeer from the Nordfjella population in South-Norway. The disease is well known in North America; however this is the first detection of CWD in Europe.
The sick female reindeer (Rangifer tarandus tarandus) was detected in the middle of March 2016 in connection with capture for GPS-collaring using helicopter performed by the Norwegian Institute for Nature Research (NINA. It died and the carcass was submitted to the Norwegian Veterinary Institute in Oslo for necropsy and laboratory examinations. It was an adult animal, says wildlife pathologist Turid Vikøren at Norwegian Veterinary Institute, who performed the necropsy.
Six more cases of CWD found in Newton County, CWD-Info.org, April 5, 2015 Six more deer from the Arkansas Game and Fish Commission’s chronic wasting disease sampling effort have turned up positive, according to the Wisconsin Veterinary Diagnostic Laboratory in Madison. This brings the total of CWD-positive cases of Arkansas deer and elk to 56. All six deer that tested positive came from Newton County inside the sampling focal area. The high number of positive results has already prompted a second sampling effort to determine whether the disease is present in other parts of the state.
Outdoors: To fight chronic wasting disease among deer, we must act now, Detroit Free Press, April 3, 2016CWD-infected deer have been found in Ingham, Clinton counties, making this problem even more dire. When a deer infected by Chronic Wasting Disease (CWD) nibbles a plant, the prion infection in its saliva absorbs into the plant’s roots and into the soil, and it emerges again with new sprouts. Should another deer graze that same trail, it will become infected with the fatal neurological disease. And Eaton County definitely is home to CWD.
Chronic Wasting Disease Cases Keep Rising In Newton Co. Deer Population, KFSM News, April 1, 2016So far, three of the elk samples have been found to be positive for CWD, the rest have been deer. Some of the CWD-positive samples came from dead or sick deer found outside the original sampling zone, which has prompted a second phase of sampling on a much larger scale.
More deer with chronic wasting disease reported, with one outside of a CWD management area, PA Live, March 26, 2016The Maryland Department of Natural Resources found another five deer with chronic wasting disease in Allegany County, just south of Bedford County in southwestern Pennsylvania. The location of the five new cases in Maryland is south of the area of Pennsylvania that has seen 17 free-ranging deer with CWD since 2013. Seven of those deer were uncovered last year.
Wisconsin leaders are ignoring the risk of chronic wasting disease, Isthmus, March 28, 2016A very rough estimate is that, since last November, around 80,000 people in Wisconsin may have been consuming deer that were infected with chronic wasting disease. And the Wisconsin Department of Natural Resources doesn’t want you to so much as even think about that. In an excellent piece, outdoor writer Patrick Durkin calls out the DNR for downplaying a dramatic increase in CWD in the Wisconsin deer herd. Based on limited testing during the 2015 deer season, about 9.5% of the herd is now infected. (That figure was under 2% in 2008.)
Five Deer Test Positive for Chronic Wasting Disease, CSD-Info.org, March 28, 2016The Maryland Department of Natural Resources has received laboratory confirmation that five white-tailed deer harvested in Allegany County tested positive for chronic wasting disease, a neurological disease in deer, bringing the total overall cases to 11. “Given that this disease is now present in the region, our wildlife biologists will continue to work diligently to document and monitor its presence, which, so far, has been limited to Allegany County. We urge citizens to only consume the meat of deer that appear healthy.”
Michigan confirms new CWD-positive findings; total is now seven deer, Michigan DNR Bulletin, March 18, 2016One of the newly confirmed CWD-positive deer is a 9-month-old male from Meridian Township (Ingham County), and the other is a 2 ¾-year-old female from Watertown Township (Clinton County).
The intensive removal of deer in these areas has a two-part benefit. One, it helps us understand prevalence rates and spread so we can make informed decisions on disease management moving forward; and two, by removing individual deer around areas with known disease occurrence, it reduces the potential for spread and accumulation in our deer herd, which has benefits not only locally, but on the periphery of the management zone as well.
News On Deer Chronic Wasting Disease Gets Worse, Grand View Outdoors, March 1, 2016 Last year there was a glimmer of hope when a potential vaccine was reported. However, in November 2015, Dr. Mary Wood, a wildlife veterinarian with Wyoming Fish and Game reported that “We have not observed a protective effect associated with this vaccine.”The magic bullet that everyone hoped for is not there — at least not yet. This was the result after a three-year trial on 38 elk in a research facility in Wyoming. There was a slight glitch at the beginning of this research and the final results won’t be known for a year, but the preliminary data does not give much hope for the vaccine. That doesn’t mean that this research was a waste of time. It could lead to other, more productive research for those looking for an answer to CWD. But for the time being, the possibility of a vaccine to slow CWD is not an option.
Deer disease confirmed in Hartley Co., WALB, Feb 28, 2016HARTLEY COUNTY, TX (KFDA) – The first case of a disease fatal to deer has been confirmed in the Panhandle. A free-ranging mule deer in Hartley County tested positive for chronic wasting disease (CWD).
Deer Killed In Clinton County May Have CWD, WILX.com, Dec 31, 2015Watertown Twp., Clinton Co. – The Michigan Department of Natural Resources says a deer killed by a bow hunter earlier this month may have Chronic Wasting Disease.
Deer disease has food banks on edge, Lansing State Journal, Nov 13, 2015All deer harvested within a nine-township core area around Meridian Township must be taken to a check station for testing. And processors who accept deer from the core area are required to isolate those carcasses from other meat.
DNR: Deer killed in Clinton Co. may have wasting disease, Detroit Free Press, Jan 4, 2016State wildlife officials say a deer killed by a bow hunter in Watertown Township this month might have been carrying chronic wasting disease. Samples of the deer — a 11/2-year-old doe — were sent to a federal laboratory in Iowa on Monday for more detailed testing.
DNR video: Wasting disease prompts tighter deer hunt rules, MLive, Sept 30, 2015Three deer have been discovered with the disease this year, all in the Lansing area. The neurological disease, which also kills elk and moose, was first found in wild deer in western states in 1985. The first Michigan infection was discovered in Kent County in 2008. The DNR developed a disease response plan in 2002.
Stricter rules are meant to stem the spread of the disease.
Chronic Wasting Disease Is Spreading, Can It Be Stopped?, Grand View Outdoors, Oct 8, 2015
“We call them Droolers and Shakers,” said Don Bates, former supervisor of chronic wasting disease operations for the Wisconsin Department of Natural Resources. Bates, now retired, said many people ignore CWD because most infected deer die alone and unseen. Although some huddle against a garage or near a dryer vent in winter to protect themselves from the cold, most die unseen and undocumented in thickets, wetlands or river bottoms. It’s getting worse at faster and higher rates than ever.”
CWD is an always-fatal brain disease. Once deer contract it, their life expectancy is about 18 to 20 months. They typically look healthy the first 16 months before showing its effects. Those signs include tremors, heavy drool, staggering and stark ribs and spinal bones outlined beneath a ratty hide. In advanced stages, they lose their fear of humans.
Map of CWD as of April 2015
Will CWD wipe out deer for future hunters?, Green Bay Press Gazette, Sept 4, 2015Like it or not, the odds of a sickly Wisconsin deer herd in 2071 are looking more likely each year. CWD prevalence in southern Wisconsin has doubled across all ages in both sexes of deer the past 13 years. In at least one area, four of every 10 adult bucks carries the disease, and in at least two other areas one in four mature bucks are infected.
Follow Illinois, not Wisconsin, to slow spreading CWD, Journal-Sentinel, Aug 19, 2015Although the Wisconsin DNR initially attempted to eradicate the disease with aggressive measures, including sharpshooters and longer hunting seasons, it now uses only monitoring and surveillance. Rates of the disease have increased substantially since Wisconsin abandoned targeted deer reduction efforts.
The difference in CWD prevalance rates in the two states is due mostly to management strategy, according to University of Illinois researchers Jan Novakofski and Michelle Green. Illinois has remained committed to reducing deer in areas with known CWD-positive animals. The IDNR also is testing deer for CWD in a wide area, hoping to find any new disease sites.
For the sampling year ending June 30, the CWD prevalence rate in Illinois was 1.2%, according to Paul Shelton, forest wildlife manager for the Illinois Department of Natural Resources. “This is a very challenging issue,” Shelton said. “We can’t declare victory, but we can say that the work we’ve been doing has helped keep the rates lower than they otherwise would be.”
Two new deer were found this week, testing positive for Chronic Wasting Disease, Michigan Emerging Disease Issues, Chronic Wasting Disease (CWD)
Weekly CWD Status Update – Updated 7/17/2015
Michigan confirms CWD in second free-ranging white-tailed deer, Michigan DNR sent this bulletin at 07/17/2015The Michigan departments of Natural Resources (DNR) and Agriculture and Rural Development (MDARD) have confirmed a second free-ranging deer in Meridian Township (Ingham County) has tested positive for chronic wasting disease (CWD), a fatal neurological disease that affects white-tailed deer, mule deer, elk and moose. This second case is a 2-year-old male found less than a mile from the initial positive female deer, confirmed this past May. Genetic testing is being conducted to see if the two deer are related.
Ten Deer Test Positive for CWD in 2014-2015Kansas Wildlife, Parks and Tourism, July 16, 2015A total of 640 deer were tested for chronic wasting disease (CWD) during the 2014-2015 seasons, and 10 of those were confirmed positive. Samples were obtained from deer killed by hunters in southcentral and southwest parts of Kansas and from sick and/or suspect deer observed in the eastern, northcentral and northwest parts of the state.
‘Surprising’ Discovery Made About Chronic Wasting Disease , Food and Safety News, June 2015According to researchers at The University of Texas Health Science Center at Houston (UTHealth), grass plants can bind, uptake and transport infectious prions. Why this is so important takes some understanding of what prions are. Much smaller than bacteria, prions are single proteins that cannot be destroyed by typical “kill strategies” such as extreme heat or ultraviolet light.
Soto’s team analyzed the retention of CWD and other infectious prion proteins and their infectivity in wheat grass roots and leaves that had been incubated with prion-contaminated material. They discovered that even highly diluted amounts of the material can bind to the roots and leaves. From there, they fed the wheat grass to hamsters, which became infected with the disease. The team also found the infectious prion proteins in plants that had been exposed to urine and feces from prion-infected hamsters and deer.
USGS Chronic Wasting Disease spreading
Chronic wasting disease spreading among deer in Michigan, KTTC News, June 17, 2015MICHIGAN – Two dozen deer have been collected in the first week of a targeted deer kill in Meridan Township, in Michigan, after chronic wasting disease killed animals in the area. According to the Lansing State Journal, experts estimate 59 deer in the township are infected. The disease is fatal and causes a mutated protein to multiply, and attack the animal’s immune system.
DNR works to contain chronic wasting disease found in Meridian Township deer, Great Lakes Echo, June 5, 2015The Michigan Department of Natural Resources says it’s found a deer in Meridian Township that’s tested positive for chronic wasting disease. It’s the first reported case of the disease in the state since 2008, and the very first time it has occurred in a wild deer population. Chronic wasting disease is not harmful to humans, but is always fatal to deer.
Deer kill under way in Meridian Township, Lansing State Journal, June 4, 2015The hunt “certainly will” continue through a lot of the summer, Stewart said, but he doesn’t anticipate it extending into hunting season. Bow season begins Oct.1. “We are in this for the long haul, unfortunately,” he added.
It’s thought that chronic wasting disease — which is not transmittable to humans — is more common in larger populations. The fatal neurological disease affects white-tailed deer, mule deer, moose and elk.
Midnight Snipers Fighting CWD, WJIMAM.com, May 27, 2015In the wake of Chronic Wasting Disease or CWD being confirmed in a wild Michigan deer, the Department of Natural Resources is moving quickly to implement an emergency plan it’s had for in place years but hoped to never use. The emergency management plan is aggressive and will likely change the dynamics of the deer population in the state for generations to come.
CWD in Michigan, Deer Michigan, May 26,2015The Michigan Department of Natural Resources has an emergency response plan for CWD, which it originally created in 2002, deployed in 2008 after a Kent County deer at a captive cervid facility tested positive for CWD, and updated in 2012 based on what it learned from that experience and from more recent science on CWD. So what is the DNR doing? What can we expect? What can we do to help? What are hunters required to do? What can’t we do? What should we do? Use the resources below to find out!
Michigan confirms first case of CWD in free-ranging white-tailed deer, Michigan DNR sent this bulletin at 05/26/2015 02:01 PM EDT:Press ReleaseThe Michigan departments of Natural Resources (DNR) and Agriculture and Rural Development (MDARD) today confirmed that a free-ranging deer in Meridian Township (Ingham County) has tested positive for chronic wasting disease (CWD), a fatal neurological disease that affects white-tailed deer, mule deer, elk and moose. This is the first time the disease has been found in Michigan’s free-ranging deer population. The disease is caused by the transmission of infectious, self-multiplying proteins (prions) contained in saliva and other body fluids of infected animals. Susceptible animals can acquire CWD by direct exposure to these fluids or from environments contaminated with these fluids or the carcass of a diseased animal. Once contaminated, research shows that soil can remain a source of infection for long periods of time, making CWD a particularly difficult disease to eradicate. Some chronically CWD-infected animals will display abnormal behaviors, progressive weight loss and physical debilitation. There is no cure; once a deer is infected with CWD, it will die.
Grass plants can transport infectious prions, Science Daily, May 15 2015“There is no proof of transmission from wild animals and plants to humans,” said lead author Claudio Soto, Ph.D., professor of neurology at UTHealth Medical School and director of the UTHealth George and Cynthia W. Mitchell Center for Alzheimer’s Disease and Other Brain Related Illnesses. “But it’s a possibility that needs to be explored and people need to be aware of it. Prions have a long incubation period.”
Soto’s team analyzed the retention of infectious prion protein and infectivity in wheat grass roots and leaves incubated with prion-contaminated brain material and discovered that even highly diluted amounts can bind to the roots and leaves. When the wheat grass was consumed by hamsters, the animals were infected with the disease. The team also learned that infectious prion proteins could be detected in plants exposed to urine and feces from prion-infected hamsters and deer.
Can DEER droppings transmit CHRONIC WASTING DISEASE to HUMANS?, Natural Unseen Hazards Blog, April 2, 2015The biggest potential problem you face in having so many deer droppings in your garden is the potential for the transmission of E. coli and chronic wasting disease (CWD), a deer and elk disease similar to mad cow disease. The Pennsylvania Game Commission’s website notes that CWD has been detected in several Pennsylvania locations since it was first found in the state in 2012. After a bit of investigating, I discovered that the jury is still out on whether and how chronic wasting disease can be transmitted to humans. That being said, both the Pennsylvania Game Commission’s website and the Center for Disease Control’s website note that there’s no evidence that CWD is transmissible to humans. But they do not recommend eating meat from a deer that has tested positive for CWD. From what I found, fecal-to-oral transmission from deer to humans has not been completely ruled out, meaning the disease could possibly be transmitted to a human if she were to touch contaminated deer excrement and then inadvertently introduce it into her mouth, but no cases of this type of transmission have ever been recorded.
Is chronic wasting disease a threat to humans?, Virology Blog, March 11, 2015Another concern is that prions of chronic wasting disease could be transmitted to cows grazing in pastures contaminated by cervids. Prions can be detected in deer saliva and feces, and contamination of grass could pass the agent on to cows. In the laboratory, brain homogenates from infected deer can transmit the disease to cows. Therefore it is possible that cervid prions could enter the human food chain through cows.
Although the risk of human infection with CWD prions appears to be low, hunters should not shoot or consume an elk or deer that is acting abnormally or appears to be sick, to avoid the brain and spinal cord when field dressing game, and not to consume brain, spinal cord, eyes, spleen, or lymph nodes. No case of transmission of chronic wasting disease prions to deer hunters has yet been reported.
10 Reasons You Don’t Want CWD in Your Woods, QDMA, Feb 17, 2015There is much confusion between CWD and hemorrhagic disease (EHD and bluetongue virus). EHD and bluetongue are serious matters in their own right, and their impact is more rapid, more visible and more dramatic. Deer carcasses pile up quickly in outbreak areas. By contrast, CWD is a slow poison, building over time, taking months or years to kill individual deer that are spreading the infection as they slowly die. Unlike the EHD and bluetongue viruses transmitted by insects, the CWD blight is steadily growing with no breaks, no recovery periods, no survivors, and no resulting immunity. The known impact sites for CWD in wild deer or elk currently include 19 states and two Canadian provinces, a list that has been growing recently. Minnesota and Maryland discovered CWD in free-roaming deer in 2011; Missouri in 2012; Pennsyvlania in 2013; and last year, Iowa. We should be concered about both EHD and CWD, but an important difference is that CWD can still be prevented from spreading to new areas. If you don’t hunt in or near regions with CWD, be very happy, and support all efforts to prevent the disease’s arrival near you. If it hits, the biological damage to the deer herd will be slow to build, but the impact on you and your hunting will likely be immediate and significant.
Four Maryland Deer Test Positive for Chronic Wasting Disease, Maryland DNR, Jan 20, 2015The Maryland Department of Natural Resources received laboratory confirmation on January 16, 2015 that four additional white-tailed deer harvested in Maryland tested positive for chronic wasting disease (CWD), bringing the total number of overall positive cases to six. The first confirmed case of CWD in Maryland was reported in February 2011 and the second was found in 2014, both from Allegany County. Maryland is one of more than 20 states and Canadian provinces with CWD documented in deer, elk or moose.
First successful vaccination against ‘mad cow’-like wasting disease in deer, Science Daily, Dec 21, 2014The study, to be published in Vaccine online Dec. 21, documents a scientific milestone: The first successful vaccination of deer against chronic wasting disease (CWD), a fatal brain disorder caused by unusual infectious proteins known as prions. Prions propagate by converting otherwise healthy proteins into a disease state.
The importance of localized culling in stabilizing chronic wasting disease prevalence in white-tailed deer populations, Preventive Veterinary Medicine, Jan 2014We addressed the functional differences between hunting and government culling programs for managing chronic wasting disease (CWD) in white-tailed deer by comparing prevalence over a 10-year period in Illinois and Wisconsin. When both Illinois and Wisconsin were actively culling from 2003 – 2007, there were no statistical differences between state CWD prevalence estimates. Wisconsin government culling concluded in 2007 and average prevalence over the next five years was 3.09 ± 1.13% with an average annual increase of 0.63%. During that same time period, Illinois continued government culling and there was no change in prevalence throughout Illinois.
Chronic wasting disease, Prion, Jan-March 2012Transmissible spongiform encephalopathies (prion diseases) in animals may be associated with a zoonotic risk potential for humans as shown by the occurrence of variant Creutzfeldt-Jakob disease in the wake of the bovine spongiform encephalopathy epidemic. Thus, the increasing exposure of humans in North America to cervid prions of chronic wasting disease (CWD) in elk and deer has prompted comprehensive risk assessments. The susceptibility of humans to CWD infections is currently under investigation in different studies using macaques as primate models. The necessity for such studies was recently reinforced when disease-associated prion protein and its seeding activity were detected in muscles of clinically inconspicuous CWD-infected white-tailed deer (WTD).
CWD: A 10-Year Retrospective, Wisconsin Dept of Natural Resources, In February 2002, the DNR was notified that three deer harvested the previous fall from Deer Management Unit 70A in western Dane County had tested positive for CWD. This discovery launched an intensive surveillance effort in Wisconsin that continues today. As of February 2012, nearly 172,000 wild white-tailed deer have been sampled, over 1,800 of which have tested CWD-positive. There appear to be two main areas of CWD infection in Wisconsin. One is centered in western Dane and eastern Iowa counties. The second is located in northern Illinois and extends into southeastern Wisconsin. Illinois first detected the presence of CWD in this area in the fall of 2002 and as of April 2011, 336 CWD-positive deer have been found.
Chronic Wasting Disease, An emerging threat, Humane Society, Oct 4, 2012In order to reduce the potential of future biological threats from this and other zoonotic diseases on a larger scale, states must ban game farms and captive hunts. The high population densities that characterize captive hunt facilities greatly increase the risk of disease transmission. The risk of CWD spreading to native populations of wildlife is taken very seriously. Thus far, testing and “depopulating” are the chosen methods of eradication.
Deer density and disease prevalence influence transmission of chronic wasting disease in white-tailed deer, Ecosphere, Jan 2013. We evaluated the influence of deer density,
landscape features, and soil clay content on transmission of chronic wasting disease (CWD) in young white-tailed deer in south-central Wisconsin, USA. We evaluated how frequency-dependent, density-dependent, and intermediate transmission models predicted CWD incidence rates in harvested yearling deer. An intermediate transmission model, incorporating both disease prevalence and density of infected deer, performed better than simple density- and frequency-dependent models. Our results indicate a combination of social structure, non-linear relationships between infectious contact and deer density, and distribution of disease among groups are important factors driving CWD infection in young deer.
Study Spells Out Spread of Brain Illness in Animals, New York Times, Sept 9, 2009There is no evidence to date that humans who hunt, kill and eat deer have developed chronic wasting disease. Nor does the prion that causes it pass naturally to other animal species in the wild. Besides mad cow and chronic wasting disease, the prion diseases include Creutzfeldt-Jakob, which leads to dementia and death in humans. Each of these diseases is caused by a different strain, and all strains behave somewhat differently.
In the case of chronic wasting disease, “it turns out prions exploit the oldest trick in the book used by pathogens and parasites,” said Mike Miller, a veterinarian at the Colorado Division of Wildlife who is an expert on chronic wasting disease.
“Fecal-oral transmission is very effective,” Dr. Miller continued. Each deer excretes about two pounds of fecal pellets a day. As wild herds move around, or captive herds are trucked between states, more soil becomes infected.
The Spread of CWD in White-tailed Deer, The BuckManager, Oct 29, 2009The finding suggests a reasonable explanation for transmission of the disease among white-tailed deer, mule deer, and possibly elk and moose in the environment. While the study reveals that prions are shed in feces of symptomatic deer as well, the discovery that the infected deer shed prions in their feces many months before they show clinical symptoms is the most unsettling. White-tailed deer, mule deer, elk and moose inadvertently consume feces and soil in the course of their daily browsing and grazing.
Prions found in feces of deer asymptomatic for chronic wasting disease, UCSF, Sept 9, 2009Scientists have discovered that deer asymptomatic for a fatal brain condition known as chronic wasting disease excrete the infectious prions that cause the disease in their feces. The finding, they say, suggests a plausible explanation for transmission of the disease among deer and, possibly, elk and moose in the environment. While the study reveals that prions are shed in feces of symptomatic deer as well, the discovery that the infected deer shed prions in their feces many months before they show clinical symptoms has particularly provocative implications.
Deer, elk and moose inadvertently consume feces and soil in the course of their daily grazing. Given this, the team set out to determine whether the animals could develop chronic wasting disease through long-term consumption of contaminated feces. They did so by measuring the amount of prions contained in the feces of orally infected deer up until the time they became symptomatic and then calculated whether prolonged exposure to the concentrations of prions in these feces would be enough to cause the disease.
Chronic Wasting Disease and Potential Transmission to Humans, CDC, June 2004 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 and Potential Transmission to Humans, CDC Emerging Infectious Diseases, June 2004Chronic 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.
"The native plants are tramped down, the bushes are gnawed, and my three-year-old grandson can't play in the back yard because of the deer droppings. If humans entered our property and exacted such a toll we would have legal recourse We're watching the curb appeal and property value decline at a time when our taxes are rising. We are without defense."
M. Holland, Ann Arbor resident