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Study finds CWD could infect humans


Mule Deer
Photo credit: Dreamstime

Since the 1960s, Chronic wasting disease (CWD) has impacted moose, elk, deer and caribou across 24 states and two Canadian provinces. It is a fatal neurological disease that can decimate herds. Because of this, states have tried to stop the spread of this deadly disease by “lethally removing” diseased animals, closing supplemental feeding stations and carefully monitoring herds.

Now, there’s another reason to be concerned.

An ongoing study led by Health Canada has discovered that “CWD has the potential to infect humans,” EnviroNews reports. Led by Dr. Stefanie Czub, head of the virology section at the Canadian Food Inspection Agency (CFIA), the study is using cynomolgus macaques: primates that are closest to humans and approved for medical research. An advisory dated April 26, 2017 states: “These findings suggest that CWD, under specific experimental conditions, has the potential to cross the human species barrier, including by enteral [oral] feeding of CWD infected muscle.”

Prior to this discovery, it was thought that CWD could only infect cervids. However, while there are no confirmed cases of CWD in humans, the Center for Disease Control strongly recommended that people not eat any infected meat. This ongoing study further solidifies the need to leave CWD-infected meat alone.

“The shockwaves are still reverberating through the scientific community because of this research,” Darrel Rowledge, Director of the Alliance for Public Wildlife (APW), told EnviroNews. “This is a wakeup call. These macaque data are stunning.”

Continued below

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CWD is one of six known animal prion diseases – five of which affect humans; mad cow disease is one of the most well-known. While the typical timeline for this type of research includes completing the study and publishing it in a peer-reviewed journal, Czub says that it was necessary to share this information with the public as soon as possible.

“This whole experiment was done to generate data for a risk assessment of chronic wasting disease, and a risk assessment is always to protect human health,” Czub told EnviroNews. “What we have so far is important enough to communicate it.”

This is the first study to look at how CWD could infect humans. Other studies have identified CWD infection pathways in mice, voles, squirrel monkeys and domestic cats.

“There’s always been a suspicion of the possibility, a hypothetical risk of transmission to humans,” Dr. Ryan Maddox, an epidemiologist with the CDC, told EnviroNews. “It’s something CDC has been keeping an eye on for a number of years.” 


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Gary C. - posted 2 years ago on 08-22-2017 10:30:19 am

Amazing that it has taken this long to confirm that a deadly family of disease known as Transmissible Spongiform Encephalopathy is a TRANSMISSIBLE DISEASE. Prion disease is prion disease. There is no meaningful species barrier between mammals (including humans).

It's time to stop dumping infectious waste on deer farms, livestock operations, farms, forests, golf courses, school grounds and other open lands. It's a public health disaster.

Although there are several pathways for deadly prion disease to infect a herd, the greatest prion pathway is being ignored. Sick deer, elk, moose and reindeer are just canaries in a proverbial coal mine. You and your family are caught in the crossfire of misinformation and mismanagement. Neurodegenerative disease is now the fastest-growing cause of death in the world. Read how the contagion is spreading among all mammals. There is no species barrier between mammals. It's time to defend the homeland from pathogens and lies.

Terry S. - posted 2 years ago on 08-22-2017 09:44:07 am

greetings hunters,

i have followed the mad cow saga (all of it including CWD), for almost 20 years daily, since my mothers demise to the hvCJD, confirmed. i refuse to sit idle by and eat tse prions. they can kill you and yours. for this, i wish to submit the most updated science on the tse prion. i post all this to blogs, i do NOT advertise or make money from this. this is for educational use. i just made a promise to mom, never forget, and never let them forget. i kindly wish to submit to you all the following, Good Luck!

*** WDA 2016 NEW YORK ***

We found that CWD adapts to a new host more readily than BSE and that human PrP was unexpectedly prone to misfolding by CWD prions. In addition, we investigated the role of specific regions of the bovine, deer and human PrP protein in resistance to conversion by prions from another species. We have concluded that the human protein has a region that confers unusual susceptibility to conversion by CWD prions.

Student Presentations Session 2

The species barriers and public health threat of CWD and BSE prions

Ms. Kristen Davenport1, Dr. Davin Henderson1, Dr. Candace Mathiason1, Dr. Edward Hoover1 1Colorado State University

Chronic wasting disease (CWD) is spreading rapidly through cervid populations in the USA. Bovine spongiform encephalopathy (BSE, mad cow disease) arose in the 1980s because cattle were fed recycled animal protein. These and other prion diseases are caused by abnormal folding of the normal prion protein (PrP) into a disease causing form (PrPd), which is pathogenic to nervous system cells and can cause subsequent PrP to misfold. CWD spreads among cervids very efficiently, but it has not yet infected humans. On the other hand, BSE was spread only when cattle consumed infected bovine or ovine tissue, but did infect humans and other species. The objective of this research is to understand the role of PrP structure in cross-species infection by CWD and BSE. To study the propensity of each species’ PrP to be induced to misfold by the presence of PrPd from verious species, we have used an in vitro system that permits detection of PrPd in real-time. We measured the conversion efficiency of various combinations of PrPd seeds and PrP substrate combinations. We observed the cross-species behavior of CWD and BSE, in addition to feline-adapted CWD and BSE. We found that CWD adapts to a new host more readily than BSE and that human PrP was unexpectedly prone to misfolding by CWD prions. In addition, we investigated the role of specific regions of the bovine, deer and human PrP protein in resistance to conversion by prions from another species.

*** We have concluded that the human protein has a region that confers unusual susceptibility to conversion by CWD prions.

*** CWD is unique among prion diseases in its rapid spread in natural populations.

*** BSE prions are essentially unaltered upon passage to a new species, while CWD adapts to the new species.

*** This adaptation has consequences for surveillance of humans exposed to CWD.

Wildlife Disease Risk Communication Research Contributes to Wildlife Trust Administration Exploring perceptions about chronic wasting disease risks among wildlife and agriculture professionals and stakeholders

you can see more evidence here ;


First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress

Stefanie Czub1, Walter Schulz-Schaeffer2, Christiane Stahl-Hennig3, Michael Beekes4, Hermann Schaetzl5 and Dirk Motzkus6 1

University of Calgary Faculty of Veterinary Medicine/Canadian Food Inspection Agency; 2Universitatsklinikum des Saarlandes und Medizinische Fakultat der Universitat des Saarlandes; 3 Deutsches Primaten Zentrum/Goettingen; 4 Robert-Koch-Institut Berlin; 5 University of Calgary Faculty of Veterinary Medicine; 6 presently: Boehringer Ingelheim Veterinary Research Center; previously: Deutsches Primaten Zentrum/Goettingen

This is a progress report of a project which started in 2009. 21 cynomolgus macaques were challenged with characterized CWD material from white-tailed deer (WTD) or elk by intracerebral (ic), oral, and skin exposure routes. Additional blood transfusion experiments are supposed to assess the CWD contamination risk of human blood product. Challenge materials originated from symptomatic cervids for ic, skin scarification and partially per oral routes (WTD brain). Challenge material for feeding of muscle derived from preclinical WTD and from preclinical macaques for blood transfusion experiments. We have confirmed that the CWD challenge material contained at least two different CWD agents (brain material) as well as CWD prions in muscle-associated nerves.

Here we present first data on a group of animals either challenged ic with steel wires or per orally and sacrificed with incubation times ranging from 4.5 to 6.9 years at postmortem. Three animals displayed signs of mild clinical disease, including anxiety, apathy, ataxia and/or tremor. In four animals wasting was observed, two of those had confirmed diabetes. All animals have variable signs of prion neuropathology in spinal cords and brains and by supersensitive IHC, reaction was detected in spinal cord segments of all animals. Protein misfolding cyclic amplification (PMCA), real-time quaking-induced conversion (RT-QuiC) and PET-blot assays to further substantiate these findings are on the way, as well as bioassays in bank voles and transgenic mice.

At present, a total of 10 animals are sacrificed and read-outs are ongoing. Preclinical incubation of the remaining macaques covers a range from 6.4 to 7.10 years. Based on the species barrier and an incubation time of > 5 years for BSE in macaques and about 10 years for scrapie in macaques, we expected an onset of clinical disease beyond 6 years post inoculation.






Risk Advisory Opinion: Potential Human Health Risks from Chronic Wasting Disease CFIA, PHAC, HC (HPFB and FNIHB), INAC, Parks Canada, ECCC and AAFC

TUESDAY, JUNE 13, 2017

PRION 2017 CONFERENCE ABSTRACT First evidence of intracranial and peroral transmission of Chronic Wasting Disease (CWD) into Cynomolgus macaques: a work in progress

TUESDAY, JULY 04, 2017


TUESDAY, JUNE 13, 2017

PRION 2017 CONFERENCE ABSTRACT Chronic Wasting Disease in European moose is associated with PrPSc features different from North American CWD


SUNDAY, JULY 16, 2017

*** Temporal patterns of chronic wasting disease prion excretion in three cervid species ***


Chronic wasting disease continues to spread Disease of cervids causing local population declines


*** USA Chronic Wasting Disease CWD TSE Prion Emergency Response Plan Singeltary et al ***

*** Using in vitro prion replication for high sensitive detection of prions and prionlike proteins and for understanding mechanisms of transmission.

Claudio Soto Mitchell Center for Alzheimer's diseases and related Brain disorders, Department of Neurology, University of Texas Medical School at Houston.

***Recently, we have been using PMCA to study the role of environmental prion contamination on the horizontal spreading of TSEs. These experiments have focused on the study of the interaction of prions with plants and environmentally relevant surfaces. Our results show that plants (both leaves and roots) bind tightly to prions present in brain extracts and excreta (urine and feces) and retain even small quantities of PrPSc for long periods of time. Strikingly, ingestion of prioncontaminated leaves and roots produced disease with a 100% attack rate and an incubation period not substantially longer than feeding animals directly with scrapie brain homogenate. Furthermore, plants can uptake prions from contaminated soil and transport them to different parts of the plant tissue (stem and leaves). Similarly, prions bind tightly to a variety of environmentally relevant surfaces, including stones, wood, metals, plastic, glass, cement, etc. Prion contaminated surfaces efficiently transmit prion disease when these materials were directly injected into the brain of animals and strikingly when the contaminated surfaces were just placed in the animal cage. These findings demonstrate that environmental materials can efficiently bind infectious prions and act as carriers of infectivity, suggesting that they may play an important role in the horizontal transmission of the disease.


Since its invention 13 years ago, PMCA has helped to answer fundamental questions of prion propagation and has broad applications in research areas including the food industry, blood bank safety and human and veterinary disease diagnosis.

*** In conclusion, the results in the current study indicate that removal of furniture that had been in contact with scrapie-infected animals should be recommended, particularly since cleaning and decontamination may not effectively remove scrapie infectivity (31), even though infectivity declines considerably if the pasture and the field furniture have not been in contact with scrapie-infected sheep for several months. As sPMCA failed to detect PrPSc in furniture that was subjected to weathering, even though exposure led to infection in sheep, this method may not always be reliable in predicting the risk of scrapie infection through environmental contamination. These results suggest that the VRQ/VRQ sheep model may be more sensitive than sPMCA for the detection of environmentally associated scrapie, and suggest that extremely low levels of scrapie contamination are able to cause infection in susceptible sheep genotypes.

Keywords: classical scrapie, prion, transmissible spongiform encephalopathy, sheep, field furniture, reservoir, serial protein misfolding cyclic amplification

Wednesday, December 16, 2015

*** Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission ***

*** Infectious agent of sheep scrapie may persist in the environment for at least 16 years ***

Gudmundur Georgsson1, Sigurdur Sigurdarson2 and Paul Brown3


Chronic Wasting Disease Prion Strain Emergence and Host Range Expansion

''Successful transmission of an emergent strain of CWD prion, H95+, into mice resulted in infection. Thus, emergent CWD prion strains may have higher zoonotic potential than common strains.''

Pathogens 2017, 6(3), 35; doi:10.3390/pathogens6030035


Evolution of Diagnostic Tests for Chronic Wasting Disease, a Naturally Occurring Prion Disease of Cervids

Nicholas J. Haley 1,*Orcid and Jürgen A. Richt 2

1Department of Microbiology and Immunology, Arizona College of Osteopathic Medicine, Midwestern University, Glendale, AZ 85308, USA
2College of Veterinary Medicine, Kansas State University (KSU), Manhattan, KS 66506, USA


Received: 30 June 2017 / Accepted: 1 August 2017 / Published: 5 August 2017

Terry S. Singeltary Sr.

James M. - posted 2 years ago on 08-22-2017 03:46:07 am

Liz, each state is different so you will need to research your specific state. In general, the state's division of wildlife field offices are collection points. It would be best to drive straight there with the deer/elk prior to butchering if possible. They remove and test lymph nodes below the base of the skull. If you have to butcher the animal to get it out of the field, you will need to leave approximately 4" of neck attached below the base of the skull.

Some states are free while others charge a nominal fee. Results are available within a few weeks.

Liz E. - posted 2 years ago on 08-21-2017 09:47:40 pm

James M. How will you have your game meat tested! I'm interested for my own knowledge.

James M. - posted 2 years ago on 08-21-2017 06:55:09 pm

I expect more of a critical eye be paid to the content of this type of article post before simply rehashing a few points from a biased source article. While the topic of CWD is uncertain I personally am going to take zero chances and get all deer/elk tested to significantly reduce my family's exposure to something that may or may not cross the species barrier.

That being said, the source article grossly misrepresents the data from Colorado. It states that 1/3 of all elk and 1/2 of all deer are CWD positive. Strangely they provide a link to the CO website that refutes their shocking claim. The one word they left out was "herd". 1/3 of all elk herds have had a positive result of those tested. The percentage of positive results per unit with confirmed CWD ranges from less than 1% up to 5%-10%. So instead of 33% of elk positive it is more like 0.2%-2.5%. That is a ridiculous order of magnitude error for any legitimate scientific based article to get wrong. It draws into question the validity of the rest of the article.

Additionally, this experiment is only partially complete and the findings have not been peer reviewed. I am surprised this site reposted the story in the manner it did without identifying the very evident flaws of the source article.