Comment by tylerjwilk00 | Hacker News Reader

Comment by tylerjwilk00 | Hacker News Reader

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I too find this disease terrifying.

Hunting of white tail deer is very popular where I am from. Everyone has family members who hunt and stock up on venison. It's very common for people to share their meat with friends and neighbors and cook venison around a camp fire. Many harvested deer have been tested and confirmed infected for at least a decade now. Most people do not get their deer tested. Certain WMU (wildlife management units) are mandated that all kills be tested. Also most people field dress their own deer which means lots of blood and fluids from the deer on their hands and clothes.

I have seen a CWD deer in the wild not far from my house. It was scrawny and shaking with the strangest look on its face [1] just walking down the middle of the road. Very abnormal behavior for a deer. It's just a matter of time before it jumps to humans.

Joe Rogan actually covered CWD on one of his podcasts [2] with a few biologists as guests. You can find videos [3] of CWD on YouTube.

1. https://www.thenews.com.pk//assets/uploads/updates/2019-02-1...

2. https://www.youtube.com/watch?v=vHOUpczwcyA

3. https://www.youtube.com/results?search_query=cwd+deer

Yeah, this is pretty terrifying. I remember reading that prions might also be communicable via optical equipment.

There's no cure for prions, and they all kill you in nasty, interesting ways. Most involve driving you slowly insane and causing your body or brain to decay. The best possible treatment is antibodies, which we don't really have yet.

I remember reading that a population of people on a pacific island had high incidence rates of kuru due to eating each other's brains after death. I also remember that after a few hundred years of doing so, some had developed a resistance.

Seeing as prions mis-fold other proteins, might something like Folding@Home be able to contribute here? I would appreciate some insight from a person with knowledge of this area.

Edit: Corrected pacific island disease from mad cow to kuru; thanks noir_lord

I think it's not mad cow disease (or the human variant CJD) you mean, is it perhaps Kuru?

You're right, I appreciate the correction.

For any one curious, here's more detail on the resistance that has been developed: http://www.virology.ws/2015/06/12/resistance-to-prion-diseas...

anything involving prions is terrifying!

Want to get really terrified? Read about the chances of prions being passed between people. The first recognized prion-STD will come one day. It may already have happened. We don't test for these things. We could all be infected with hundreds of prions without knowing it. What pushes them into "disease" territory is negative symptoms.

But the upside is that prions are nothing new. Although we may not appreciate our defenses, the fact that we are all still alive is reason to believe we evolved some form of resistance to them.

What freaked me out was learning that it is extremely difficult to sterilize surgical equipment such that prions are removed. If you are operated on with surgical equipment that was previously used on a person infected with prions (I'm talking about human prions here and not deer prions), even if the equipment was thoroughly sterilized, the prions are almost certainly still there and can be transferred to you.

It reminds me of the recent discussions around eyes and prions:

"Infectious 'Prions' Found in the Eyes of Patients with Fatal Brain Disease"

"The results also raise concern about the potential for the disease to spread through routine eye exams or eye surgeries, during which equipment could become contaminated with prions, the researchers said."

https://www.livescience.com/64140-creutzfeldt-jakob-disease-...

hmm non-medical info here, but .. the washing action is important in cleaning, not just chemicals and heat.. many infections have to pass a certain critical volume to catch on.. no idea about prions specifically, but be careful about getting upset.. it is a problem itself

The hypothesis for many prion diseases is that of "seeding" whereby a small number (or maybe even a single) prion protein acts as a template to induce misfolding of other proteins with similar sequence but native folds [1,2]. This causes a chain reaction in the proliferation of the prion protein inside the cell, and then in other cells as prion proteins are transported/secreted to the surrounding tissue.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3665718/#S1titl... [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5449729/

There is an advantage in thinking about prions, and proteins more generally, as crystals rather than biological systems. A vat of fluid can sit for decades without ever forming a crystal. But then the addition of a single seed can give rise to an infinitely large, growing, structure.

>whereby a small number (or maybe even a single) prion protein acts as a template to induce misfolding of other proteins

So, maybe Vonnegut was onto something when he wrote Cat's Cradle

Prions are more like a persistent toxic chemical than any virus or bacteria.

Joe was the first thing I thought of. I wonder how he handles this in his own hunting. Does he get them tested?

How difficult and expensive is it to test a deer in the field after hunting it?

`It's just a matter of time before it jumps to humans.`

... thats not how that works.

If you read the article, this disease, like it’s relative Mad Cow Disease, can probably infect humans, but is not likely to surface until many years after infection.

Actually the parent is correct. "That's not how it works". Specifically deer prions (but not other cervids like elk) don't seem to be transmissible to cows, both in the lab and in the wild, and not to mice or humans in the lab. It goes in both ways IIRC, cows nor mice can't go to deer.

Here's a citation for that: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4981193/

If it appeared to be transmissible to humans, there would be much stronger recommendations against eating venison, like with prion diseases in cows.

I do believe that cwd can jump to humans can jump to humans

Vulnerability to prion diseases is not as universal in human populations as with bacterial and viral infections - for example it’s been observed that people with certain genes never develop vCJD from eating BSE-infected meat (or at least their genes postpone the onset by at least a few decades).

AFAIK there's no direct evidence of prion diseases jumping species. The classic studies of scrapie prions failed to show cross-species transmission even with direct injection of infected material into the brains of rodents.

Everyone assumes BSE prions from cows are causing CJD in humans, but an alternative explanation is that organized crime was disposing human bodies in hamburger factories, and CJD is just caused by human prions.

There was at least one cluster of vCJD (in Queniborough) traced to a small traditional slaughter house that was providing to butcher shops, and that cross contamination was occurring because in a slaughter/butchering operation with only a few people it is much easier for the prions to be carried from the brain/spinal tissue to the expensive steaks. A consequence of this was that all small abattoirs in the United Kingdom went out of business.

So your theory has at least one strong counter example

"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."

https://www.foodsafetynews.com/2015/06/researchers-make-surp...

If you read the article instead of the press release, you'll see that Soto's group showed that wheatgrass can be contaminated by hamster prions or CWD prions, but that they only showed transmission of hamster prions to hamsters through exposure to the contaminated wheatgrass. That's not cross-species transmission.

https://www.cell.com/cell-reports/abstract/S2211-1247(15)004...

"Everyone assumes BSE prions from cows are causing CJD in humans, but an alternative explanation is that organized crime was disposing human bodies in hamburger factories, and CJD is just caused by human prions."

Yes, that is indeed an alternative explanation, but has it actually been proposed seriously and is there any reason to believe that has ever happened ? I am genuinely curious...

shrug I don't recall seeing it in print anywhere. I've mentioned it to colleagues who study prions, and they're grossed out by the idea, but didn't think it was impossible.

I suppose you could try testing samples of hamburger for human DNA, but it would be hard to rule out innocent low levels of contamination from household dust (mostly human skin cells). Considering prions are infectious at such very low concentrations I'm not sure if any assay could rule it out.

4 paragraphs down in the main article talks about this. Yeah they don't "jump" if that's your concern. But have you ever licked your fingers without washing your hands? Are you a hunter that might have deer blood on your hands?

Doesn't have to be blood, you can just eat the stuff. That's how mad cow disease spreads to humans. Cooking doesn't kill prions.

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