Deer disease may some day infect people, expert warns

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Deer with Chronic Wasting Disease. Image: Terry Kreeger, Wyoming Game and Fish and Chronic Wasting Disease Alliance.

By Cassidy Hough

A public health scientist recently warned Minnesota legislators that chronic wasting disease in deer may soon spread to humans.

Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy, asked the lawmakers for funding to develop a more advanced and timely chronic wasting disease test.

Such a test will make the human consumption of disease-infected deer less likely, he said.

“It is probable that human cases of chronic wasting disease associated with consumption of chronic wasting disease contaminated meat will be documented in years ahead,” Osterholm said.

Chronic wasting disease attacks the brains of deer, according to the Centers for Disease Control and Prevention. It is spread through contact and causes drastic weight loss and lack of coordination. Stricken deer also do not fear people.

As of March 6, the disease has been found in two provinces in Canada and 24 states in the United States, including Minnesota, Michigan, Illinois, Wisconsin, Pennsylvania and New York, according to the Centers for Disease Control and Prevention.

“It’s possible the number of human cases will be substantial, and will not be isolated events,” Osterholm said.

Not everyone agrees. There’s a lot of mixed information when it comes to the topic of chronic wasting disease spreading to humans, according to Matt Dunfee, director of the Chronic Wasting Disease Alliance, a group that promotes responsible communication about chronic wasting disease.

“To date, no evidence indicates that humans are susceptible to chronic wasting disease and there appears to be a good species barrier,” Dunfee said. This means the disease isn’t likely to spread to new species.

But the same was said about mad cow disease, Osterholm said.

“To claim that there hasn’t yet been transmission tells us little,” Osterholm said. He compared chronic wasting disease to mad cow disease, which took 10 years for human cases to appear after it first appeared in cattle in Great Britain. It comes from the same family of diseases as chronic wasting disease, Osterholm said. That’s why the science community is concerned.

Although models have shown that chronic wasting disease could jump species as mad cow disease did, that still doesn’t tell us much, said Bryan Richards, emerging disease coordinator at the University of Wisconsin-Madison.

“Models are just that,” Richards said. “They are abstractions of reality meant to help guide our perception and risk, but none of these research studies that have been done directly tell us what to think or what to expect.”

How can you minimize the risk of contracting chronic wasting disease?

The Centers for Disease Control and Prevention suggest not handling or eating deer or elk that are acting strange or look sick. It also advises hunters to wear gloves when handling dead animals and to check state and wildlife public guidelines to see if testing animals for chronic wasting disease is recommended or required in your area. Regardless if people will contract chronic wasting disease, scientists agree that the public needs to be educated on how to slow the spread.

The disease is likely spreading into new areas because of humans, said Kelly Straka, state wildlife veterinarian for the Michigan Department of Natural Resources. Humans dispose of carcasses and bring live infected animals into unaffected areas, which accelerates the expansion.

The disease also likely exists undetected in some states, Straka said. Because we can’t test live animals, the disease is hard to track. This puts states like Ohio and Indiana, which border contaminated states, at a high risk of unknowingly housing infected herds.

2 thoughts on “Deer disease may some day infect people, expert warns

  1. or, cwd might have already infected humans and is being misdiagnosed as sporadic cjd…

    > However, to date, no CWD infections have been reported in people.

    key word here is ‘reported’. science has shown that CWD in humans will look like sporadic CJD. SO, how can one assume that CWD has not already transmitted to humans? they can’t, and it’s as simple as that. from all recorded science to date, CWD has already transmitted to humans, and it’s being misdiagnosed as sporadic CJD. …terry


    *** These results would seem to suggest that CWD does indeed have zoonotic potential, at least as judged by the compatibility of CWD prions and their human PrPC target. Furthermore, extrapolation from this simple in vitro assay suggests that if zoonotic CWD occurred, it would most likely effect those of the PRNP codon 129-MM genotype and that the PrPres type would be similar to that found in the most common subtype of sCJD (MM1).***

    Chronic Wasting Disease CWD TSE Prion aka mad deer disease zoonosis

    We hypothesize that:

    (1) The classic CWD prion strain can infect humans at low levels in the brain and peripheral lymphoid tissues;

    (2) The cervid-to-human transmission barrier is dependent on the cervid prion strain and influenced by the host (human) prion protein (PrP) primary sequence;

    (3) Reliable essays can be established to detect CWD infection in humans; and

    (4) CWD transmission to humans has already occurred. We will test these hypotheses in 4 Aims using transgenic (Tg) mouse models and complementary in vitro approaches.


    here is the latest;


    Oral transmission of CWD into Cynomolgus macaques: signs of atypical disease, prion conversion and infectivity in macaques and bio-assayed transgenic mice

    Hermann M. Schatzl, Samia Hannaoui, Yo-Ching Cheng, Sabine Gilch (Calgary Prion Research Unit, University of Calgary, Calgary, Canada) Michael Beekes (RKI Berlin), Walter Schulz-Schaeffer (University of Homburg/Saar, Germany), Christiane Stahl-Hennig (German Primate Center) & Stefanie Czub (CFIA Lethbridge).

    To date, BSE is the only example of interspecies transmission of an animal prion disease into humans. The potential zoonotic transmission of CWD is an alarming issue and was addressed by many groups using a variety of in vitro and in vivo experimental systems. Evidence from these studies indicated a substantial, if not absolute, species barrier, aligning with the absence of epidemiological evidence suggesting transmission into humans. Studies in non-human primates were not conclusive so far, with oral transmission into new-world monkeys and no transmission into old-world monkeys. Our consortium has challenged 18 Cynomolgus macaques with characterized CWD material, focusing on oral transmission with muscle tissue. Some macaques have orally received a total of 5 kg of muscle material over a period of 2 years.

    After 5-7 years of incubation time some animals showed clinical symptoms indicative of prion disease, and prion neuropathology and PrPSc deposition were detected in spinal cord and brain of some euthanized animals. PrPSc in immunoblot was weakly detected in some spinal cord materials and various tissues tested positive in RT-QuIC, including lymph node and spleen homogenates. To prove prion infectivity in the macaque tissues, we have intracerebrally inoculated 2 lines of transgenic mice, expressing either elk or human PrP. At least 3 TgElk mice, receiving tissues from 2 different macaques, showed clinical signs of a progressive prion disease and brains were positive in immunoblot and RT-QuIC. Tissues (brain, spinal cord and spleen) from these and pre-clinical mice are currently tested using various read-outs and by second passage in mice. Transgenic mice expressing human PrP were so far negative for clear clinical prion disease (some mice >300 days p.i.). In parallel, the same macaque materials are inoculated into bank voles.

    Taken together, there is strong evidence of transmissibility of CWD orally into macaques and from macaque tissues into transgenic mouse models, although with an incomplete attack rate.

    The clinical and pathological presentation in macaques was mostly atypical, with a strong emphasis on spinal cord pathology.
    Our ongoing studies will show whether the transmission of CWD into macaques and passage in transgenic mice represents a form of non-adaptive prion amplification, and whether macaque-adapted prions have the potential to infect mice expressing human PrP.

    The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD..

    ***> The notion that CWD can be transmitted orally into both new-world and old-world non-human primates asks for a careful reevaluation of the zoonotic risk of CWD. <***


    P190 Human prion disease mortality rates by occurrence of chronic wasting disease in freeranging cervids, United States

    Abrams JY (1), Maddox RA (1), Schonberger LB (1), Person MK (1), Appleby BS (2), Belay ED (1) (1) Centers for Disease Control and Prevention (CDC), National Center for Emerging and Zoonotic Infectious Diseases, Atlanta, GA, USA (2) Case Western Reserve University, National Prion Disease Pathology Surveillance Center (NPDPSC), Cleveland, OH, USA..

    SEEMS THAT THEY FOUND Highly endemic states had a higher rate of prion disease mortality compared to non-CWD


    P172 Peripheral Neuropathy in Patients with Prion Disease

    Wang H(1), Cohen M(1), Appleby BS(1,2) (1) University Hospitals Cleveland Medical Center, Cleveland, Ohio (2) National Prion Disease Pathology Surveillance Center, Cleveland, Ohio..

    IN THIS STUDY, THERE WERE autopsy-proven prion cases from the National Prion Disease Pathology Surveillance Center that were diagnosed between September 2016 to March 2017,


    included 104 patients. SEEMS THEY FOUND THAT The most common sCJD subtype was MV1-2 (30%), followed by MM1-2 (20%),


    THAT The Majority of cases were male (60%), AND half of them had exposure to wild game.


    see more on Prion 2017 Macaque study from Prion 2017 Conference and other updated science on cwd tse prion zoonosis below…terry

    THURSDAY, OCTOBER 04, 2018

    Cervid to human prion transmission 5R01NS088604-04 Update

    MONDAY, FEBRUARY 25, 2019


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