11 ms·

Prion disease is exceedingly rare. CJD is the most common, with an incidence of 1 per 1,000,000 person-years worldwide, inclusive of all transmission vectors (i

Prion disease is exceedingly rare. CJD is the most common, with an incidence of 1 per 1,000,000 person-years worldwide, inclusive of all transmission vectors (including medical procedures). Iatrogenic transmission is a rarer subset still: the riskiest transplants (with respect to CJD) are in the central nervous system. The UK tracked their transmission rates from 1970 to 2003 (a long period is needed because surgical transmission usually occurs in folks with long incubation periods - up to ten years or so) for dura transplants (something that goes into the CNS) and found a total of eight. This article is one good step above scare-mongering, but only one.

fallingknife 8y ago
Infectious disease is one area where fear of the unknown is rational. We don't just need to defend against existing diseases, but also diseases yet to emerge. Just because CJD is rare doesn't mean that the next prion disease will be, so it would make sense to take measures to prevent transmission of prions now.
- arkades 8y ago
  We take measures now, for tissues where prions are a possible transmission risk. The article mis-represented that. But: (1) there are only so many resources to go around. Should we be devoting them to vanishingly rare things rather than things that might actually affect you? (2) prions will never be a wildfire plague. They have little or no tranmissive ability, by nature of being absolutely naked protein. One step up from that - encoding the protein for space constraints and encapsulating it - is called a virus.
  - travisoneill1 8y ago
    The example in the article has very little transmissive ability because it grows in the brain and eyes. If there were a respiratory prion disease that could be much different. By nature of being a protein they are simpler and harder to eliminate than bacteria or viruses: > In a particularly vexing twist, prions are also nearly impervious to destruction, even when attacked using a strenuous combination of disinfectants, heat, and pressure.
    - dahfizz 8y ago
      > If there were a respiratory prion disease that could be much different. Not really. The point your parent is making is that prions themselves don't reproduce like viruses and bacteria. Its basically impossible for a large scale breakout to occur and spread.
      - DennisP 8y ago
        But they do reproduce, by causing other proteins to misfold. If they didn't reproduce at all, then ingesting a few prions wouldn't cause any problems. They can't reproduce outside of the body, but neither can viruses.
        jamiek88 8y ago
        Yes but they can only warp their own specific kind of protein not take over an entire reproductive ability of the native cell. It’s orders of magnitude less reproduction.
      - ergothus 8y ago
        Can you explain why? I'm not saying this is wrong, but they definitely replicate (by encountering and warping other proteins), so are you (and grandparent) saying that the replication rate is too slow? If so, why? Are you saying we have no means of transmitting proteins? (that sounds wrong, though I've been wrong before) From my (ignorant, despite being interested in prions for decades now) perspective, you have something that (1) can replicate, (2) is durable (3) is harmful, and only the relative rarity of prions in general (because 1 and 3 are physically unusual to combine) have kept them from being a general problem. As we tinker with DNA and thus look into creating new proteins and factors that would influence protein-folding, I'd think it's worth taking the matter seriously (though not fear-mongering), certainly as part of our need to understand proteins better anyway. What are my faulty assumptions?
        PeterisP 8y ago
        A prion can't arbitrary replicate from "food" or "host", its replication is more like a damaged version of protein X that can damage that same protein X if it encounters it. In many aspects it stays the same protein - the exact same DNA, the exact same sequence, just folded differently. A virus can overtake a cell and mobilize its resources to create a bajillion copies of that virus. A prion can transform only as much copies of that protein as that cell has made in its normal processes.
  - zaarn 8y ago
    Nitpick but the step between virus and prion is a viroid; a naked piece of RNA. They mostly exist in plants to my knowledge and are basically the smallest possible infectious disease. The smallest viroids clock in at around 120 base pairs (240 nucleotides).
    - tossandturn 8y ago
      Prions are like gamma-induced bit flips, Viroids are like small code patches, and Viruses are self-deploying code patches.
      - jvanderbot 8y ago
        What blows my mind is these aren't really analogies, they are in fact mostly truth.
        thinkpad20 8y ago
        To be precise, these aren’t really analogies, they are in fact similes. :)
        kenbellows 8y ago
        To be precise, similes are a type of analogy
    - selimthegrim 8y ago
      What's a virion? https://www.theguardian.com/society/2018/dec/10/mysterious-paralyzing-illness-children-record-total-cdc https://www.theguardian.com/society/2018/dec/10/mysterious-p...
      - arkades 8y ago
        A virion is the singular noun for a viral particle. The viral genetic material plus capsid equal an individual virion.
      - 8y ago
  - nwallin 8y ago
    > (2) prions will never be a wildfire plague. They have little or no tranmissive ability, by nature of being absolutely naked protein. Chronic wasting disease (CWD) (affects deer) can be transmitted by infected saliva. One of the symptoms of symptoms of CWD is excessive saliva production. It is very transmissible, and is devastating captive populations of deer, although it is relatively rare in the wild. I think if a similar TSE affected humans, spreadable by infected saliva, it would absolutely be a wildfire plague. https://en.wikipedia.org/wiki/Chronic_wasting_disease https://en.wikipedia.org/wiki/Chronic_wasting_disease
    - arkades 8y ago
      That is interesting, and new to me. I’ll have to read up on it more. Thank you for the link.
    - subroutine 8y ago
      Is there any mammalian prion disease not linked to the PRNP gene (which is fairly conserved across mammals)? At first I assumed that 'prions' came in many flavors, like virus. However from my brief lit search, it seems like people are talking about (p)rion proteins as if they were't all (P)rion proteins (PRNP). If all mammalian 'prion' disease can be traced to a single conserved gene, I think the risk of another 'prion-like' disease cropping up is pretty low. But then again, who knows? Prion disease still seems shrouded mystery, which I find odd given (1) how inherently interesting this topic seems, and (2) we've gotten really, really good at molecular biology. I feel like we are missing a key piece of the puzzle when it comes to understanding prion disease. The literature seems to want people to conceptualize the disease etiology as such: an alternately folded (disease causing) variant of PRNP protein (PrPs) bumps into a normal version of PRNP (PrPc), causing a normal copy of PrPc to also misfold into PrPs. Rinse, repeat. So you can basically think of it like an enzyme that catalyzes a conformational change on versions of itself, in a feed-forward cascade. I feel like an alternative hypothesis however, could be one of an autoimmune response. The mammalian immune system, particularly the antibody system, is mind blowing. This system can recognize virtually any foreign protein -- it can even recognize specific sub-moieties and conformations of proteins (antigens). It must, do this while never mistaking an endogenous protein to be foreign; if it does, you get an autoimmune disease. My idea is basically that PrPs is just slightly different enough from PrPc to get tagged as foreign by the antibody system (which it absolutely can do, given that we can perform western blots to detect the PrPs variant), but also just similar enough for the antibody system to mistake some endogenous PRNP for the foreign version.
  - fao_ 8y ago
    > (2) prions will never be a wildfire plague. They have little or no tranmissive ability Mad Cow Disease was caused by a prion[0]. [0]:https://en.wikipedia.org/wiki/Bovine_spongiform_encephalopathy https://en.wikipedia.org/wiki/Bovine_spongiform_encephalopat...
    - mirimir 8y ago
      And it was spread by the livestock industry.
- sandworm101 8y ago
  It is also an are where our innate fears, fears that modern society tells us are unacceptable, might have a place. There is a deep-seated fear of diseased people that once kept us healthy. Modern science has given us an understanding of disease that means there is often no need to physically separate paints where we know the disease is not easily transmitted. The shunning of an aids victim, or a child with cancer, is totally unacceptable in polite society. But prions, and especially research into possible links to various forms of dementia, suggest some dark futures. Maybe it isn't a great idea for the kids to visit grandma in hospital.
  - whiddershins 8y ago
    Nitpick note: The phrase is actually “deep seated.”
    - sandworm101 8y ago
      You are correct. I've heard it both ways and ascribed slightly different meanings, but deep-seated was what I meant.
    - 0db532a0 8y ago
      Oxford, Cambridge and Merriam-Webster say no.
      - nkurz 8y ago
        Why do you say this? And why phrase it so tersely? Merriam-Webster at least (the only one I've checked) says that "deep-seated" is the only correct version: Definition of deep-seated 1 : situated far below the surface 2 : firmly established https://www.merriam-webster.com/dictionary/deep-seated “deep-seeded” The word you've entered isn't in the dictionary. https://www.merriam-webster.com/dictionary/deep-seeded
        0db532a0 8y ago
        I was trying to make it clear that whiddershins was wrong to say that ‘deep seated’ is the correct usage in contrast to ‘deep-seated’ when Oxford, Cambridge and Merriam-Webster say that ‘deep-seated’ is indeed a correct usage. P.S. Inconsistency: I assumed that whiddershins was complaining about the hyphen, rather than correcting ‘seeded’, which had been changed to ‘seated’ by the time I first saw it.
- mattmaroon 8y ago
  I don't think that's true. Prions aren't bacteria or viruses that evolve and transmit. They're mostly just a misfolded protein that occurs spontaneously. (They can then be transmitted.) I'm not sure there will ever be a prion that hasn't already existed, whereas I am sure there will be new viruses and bacteria.
  - wetpaws 8y ago
    With the same effect I can argue that viruses and bacteria are just misarranged RNA :)
  - darpa_escapee 8y ago
    If they can replicate imperfectly, they're subject that evolutionary processes.
    - dahfizz 8y ago
      They don't replicate. Prions can't themselves make more prions like viruses do.
      - mattmaroon 8y ago
        I think the main difference is an imperfectly-replicated virus or bacteria might still be viable. A prion only makes itself. Even if it replicated imperfectly, the odds of a slightly different misfolded protein becoming another prion are vanishingly small (otherwise we'd all be dead) because there probably just are very, very few configurations possible. The vast majority of misfolded proteins just do nothing. There are several billion humans who are each replicating millions of copies of each of the 20,000 or so proteins during their lifetimes. It seems pretty unlikely that there are many misfolds that haven't occurred. It's just that only a handful become prions. And even if they do, prions are thankfully very hard to communicate (again, we'd all be dead if they weren't).
      - thfuran 8y ago
        They can induce correctly-folded proteins to misfold, effectively replicating.
- greglindahl 8y ago
  Is there someone advocating that we don't take measures now? Because we do take measures now. Example: there are a bunch of rules about what you can feed cows, and how to keep their nervous tissues out of meat at slaughter time.
- dingby 8y ago
  Your “next prion disease” is entirely hypothetical. Given that, it is pure speculation how to prevent its transmission. Why would you assume specific precautions taken would apply?
  - travisoneill1 8y ago
    The same way standard protocols are used to prevent transmission of viruses & bacteria. Apparently they don't work on prions: > In a particularly vexing twist, prions are also nearly impervious to destruction, even when attacked using a strenuous combination of disinfectants, heat, and pressure.
- Retra 8y ago
  The fear may be rational, but the response to it needs to be rational as well. That means treating the things that are known to do the most damage currently, while maintaining containment procedures that can handle your black swan epidemics.
sillypuddy 8y ago
Is alzheimers a prion disease, or maybe just Prions are involved?
- tshannon 8y ago
  I believe Alzheimers is recognized as a metabolic disease now (some have even said Type 3 diabetes). It's in no way related to Prions.
  - dingby 8y ago
    The diabetes/metabolic theory was one pitched theory, and it isn’t even a terribly mainstream one. There is no consensus that Alzheimer’s is a “metabolic disease”. Even thought ApoE is implicated, that association could be explained by numerous mechanism, even viral.
    - tshannon 8y ago
      Thanks for clarifying. I'm no expert just passing on things I've read. Regardless, it's unrelated to prions.
  - jelling 8y ago
    No expert, but the latest studies have been about the correlation with the herpes virus and how the plaque build-ups that are part of Alzheimer's may be the immune system's attempt to protect the brain.
- adamb 8y ago
  My understanding is that there is some evidence that Alzheimer's is transmissible (e.g. higher rate of incidence in caregivers and neurosurgeons), but more study is needed.
  - Fomite 8y ago
    There's also been observations of particularly large amounts of certain human herpes viruses in the brains of Alzheimer's patients.
CompelTechnic 8y ago
The article does a good job of mentioning small likelihoods but large stakes, and is intellectually honest in doing so.
davemp 8y ago
> This article is one good step above scare-mongering, but only one. I agree. Could a moderator please change the title at the least? "Prions, A Rare and Lethal Infection, ..." would be slightly better.
- davemp 8y ago
  In lue of the downvotes, would anyone like to defend the efficacy of the article's title?
ouid 8y ago
There is a great hypothesis that I remember my dad telling me recently, although I can't remember where he heard it from, that the reason that prion disease is so rare in humans is because we're, historically, very cannibalistic, so resistance to prions was heavily selected for.
- subroutine 8y ago
  The very opposite of this hypothesis is actually more likely to be true. Kuru is a manifestation of this same prion disease (PRNP gene variant disease) that is essentially only found in people from New Guinea who practiced a form of cannibalism in which they ate the brains of dead people as part of a funeral ritual.
  - ouid 8y ago
    This is exactly the wrong interpretation. We know that cannibalism causes prion disease, and we have known that for as long as we have known about prion disease. the question is not whether cannibalism causes prion disease, which it definitely does, but whether past cannibalism was common enough to have selected for some innate resistance to it. http://www.virology.ws/2015/06/12/resistance-to-prion-disease-in-humans/ http://www.virology.ws/2015/06/12/resistance-to-prion-diseas...
    - subroutine 8y ago
      Like you said, we know that cannibalism causes prion disease. We know this. Thus, we are not resistant to it. So from an evolutionary perspective you could make a strong argument that what actually happened was that those humans who didn't engage in cannibalism and die of prion disease were heavily selected for. Which is probably why you don't see many humans eating the dead. Now that last bit is speculation, but all this is speculation. But based on my own introspection, I'm imagining myself stumbling upon a recently dead human corpse, I'm almost certain my innate reaction -- (well, almost surely innate, and not socialized, since I've never been explicitly taught how to react in such a situation) -- is that I'm definitely not going to fucking eat that corpse. In fact, the only humans that do seem to still engage in cannibalism do it out of some social ritual.
g3cko_ 8y ago
An incidence of 1 per 1,000,000 may not seem that scary, what are the odds of knowing someone who gets CJD? Obviously, much greater.
bimr 8y ago
On the contrary, this falls within Nassim Taleb's Minority Rule. Prions, being nearly indestructable, are an intransigent minority that will eventually hold sway over the rest of us. Many on this board point to the inelasticity of their transmissible potential and call this fear-mongering. However, it is that same inelasticity that makes them intransigent. Once they have compromised an instrument, that instrument will remain compromised until each prion has specifically been destroyed. When you pair that intransigence with its lengthy incubation period, you actually have a force multiplier that, while not viral, would be scary enough to change behavior. Fortunately, the article hints that retinal scans may eventually be used for initial diagnosis.
Terr_ 8y ago
> Prion disease is exceedingly rare. Isn't that begging the question? I mean, the author's concern seems to be that the prevailing belief hasn't been well-tested compared to the potential impact of it being wrong. It's already happened before: There was a period of time when most medical practitioners were adamant that their actions could possibly be transferring disease, and it was an uphill fight to get regular disinfectants and hand-washing.

fallingknife 8y ago

Infectious disease is one area where fear of the unknown is rational. We don't just need to defend against existing diseases, but also diseases yet to emerge. Just because CJD is rare doesn't mean that the next prion disease will be, so it would make sense to take measures to prevent transmission of prions now.

arkades 8y ago
We take measures now, for tissues where prions are a possible transmission risk. The article mis-represented that. But: (1) there are only so many resources to go around. Should we be devoting them to vanishingly rare things rather than things that might actually affect you? (2) prions will never be a wildfire plague. They have little or no tranmissive ability, by nature of being absolutely naked protein. One step up from that - encoding the protein for space constraints and encapsulating it - is called a virus.
- travisoneill1 8y ago
  The example in the article has very little transmissive ability because it grows in the brain and eyes. If there were a respiratory prion disease that could be much different. By nature of being a protein they are simpler and harder to eliminate than bacteria or viruses: > In a particularly vexing twist, prions are also nearly impervious to destruction, even when attacked using a strenuous combination of disinfectants, heat, and pressure.
  - dahfizz 8y ago
    > If there were a respiratory prion disease that could be much different. Not really. The point your parent is making is that prions themselves don't reproduce like viruses and bacteria. Its basically impossible for a large scale breakout to occur and spread.
    - DennisP 8y ago
      But they do reproduce, by causing other proteins to misfold. If they didn't reproduce at all, then ingesting a few prions wouldn't cause any problems. They can't reproduce outside of the body, but neither can viruses.
      - jamiek88 8y ago
        Yes but they can only warp their own specific kind of protein not take over an entire reproductive ability of the native cell. It’s orders of magnitude less reproduction.
    - ergothus 8y ago
      Can you explain why? I'm not saying this is wrong, but they definitely replicate (by encountering and warping other proteins), so are you (and grandparent) saying that the replication rate is too slow? If so, why? Are you saying we have no means of transmitting proteins? (that sounds wrong, though I've been wrong before) From my (ignorant, despite being interested in prions for decades now) perspective, you have something that (1) can replicate, (2) is durable (3) is harmful, and only the relative rarity of prions in general (because 1 and 3 are physically unusual to combine) have kept them from being a general problem. As we tinker with DNA and thus look into creating new proteins and factors that would influence protein-folding, I'd think it's worth taking the matter seriously (though not fear-mongering), certainly as part of our need to understand proteins better anyway. What are my faulty assumptions?
      - PeterisP 8y ago
        A prion can't arbitrary replicate from "food" or "host", its replication is more like a damaged version of protein X that can damage that same protein X if it encounters it. In many aspects it stays the same protein - the exact same DNA, the exact same sequence, just folded differently. A virus can overtake a cell and mobilize its resources to create a bajillion copies of that virus. A prion can transform only as much copies of that protein as that cell has made in its normal processes.
- zaarn 8y ago
  Nitpick but the step between virus and prion is a viroid; a naked piece of RNA. They mostly exist in plants to my knowledge and are basically the smallest possible infectious disease. The smallest viroids clock in at around 120 base pairs (240 nucleotides).
  - tossandturn 8y ago
    Prions are like gamma-induced bit flips, Viroids are like small code patches, and Viruses are self-deploying code patches.
    - jvanderbot 8y ago
      What blows my mind is these aren't really analogies, they are in fact mostly truth.
      - thinkpad20 8y ago
        To be precise, these aren’t really analogies, they are in fact similes. :)
        kenbellows 8y ago
        To be precise, similes are a type of analogy
  - selimthegrim 8y ago
    What's a virion? https://www.theguardian.com/society/2018/dec/10/mysterious-paralyzing-illness-children-record-total-cdc https://www.theguardian.com/society/2018/dec/10/mysterious-p...
    - arkades 8y ago
      A virion is the singular noun for a viral particle. The viral genetic material plus capsid equal an individual virion.
    - 8y ago
- nwallin 8y ago
  > (2) prions will never be a wildfire plague. They have little or no tranmissive ability, by nature of being absolutely naked protein. Chronic wasting disease (CWD) (affects deer) can be transmitted by infected saliva. One of the symptoms of symptoms of CWD is excessive saliva production. It is very transmissible, and is devastating captive populations of deer, although it is relatively rare in the wild. I think if a similar TSE affected humans, spreadable by infected saliva, it would absolutely be a wildfire plague. https://en.wikipedia.org/wiki/Chronic_wasting_disease https://en.wikipedia.org/wiki/Chronic_wasting_disease
  - arkades 8y ago
    That is interesting, and new to me. I’ll have to read up on it more. Thank you for the link.
  - subroutine 8y ago
    Is there any mammalian prion disease not linked to the PRNP gene (which is fairly conserved across mammals)? At first I assumed that 'prions' came in many flavors, like virus. However from my brief lit search, it seems like people are talking about (p)rion proteins as if they were't all (P)rion proteins (PRNP). If all mammalian 'prion' disease can be traced to a single conserved gene, I think the risk of another 'prion-like' disease cropping up is pretty low. But then again, who knows? Prion disease still seems shrouded mystery, which I find odd given (1) how inherently interesting this topic seems, and (2) we've gotten really, really good at molecular biology. I feel like we are missing a key piece of the puzzle when it comes to understanding prion disease. The literature seems to want people to conceptualize the disease etiology as such: an alternately folded (disease causing) variant of PRNP protein (PrPs) bumps into a normal version of PRNP (PrPc), causing a normal copy of PrPc to also misfold into PrPs. Rinse, repeat. So you can basically think of it like an enzyme that catalyzes a conformational change on versions of itself, in a feed-forward cascade. I feel like an alternative hypothesis however, could be one of an autoimmune response. The mammalian immune system, particularly the antibody system, is mind blowing. This system can recognize virtually any foreign protein -- it can even recognize specific sub-moieties and conformations of proteins (antigens). It must, do this while never mistaking an endogenous protein to be foreign; if it does, you get an autoimmune disease. My idea is basically that PrPs is just slightly different enough from PrPc to get tagged as foreign by the antibody system (which it absolutely can do, given that we can perform western blots to detect the PrPs variant), but also just similar enough for the antibody system to mistake some endogenous PRNP for the foreign version.
- fao_ 8y ago
  > (2) prions will never be a wildfire plague. They have little or no tranmissive ability Mad Cow Disease was caused by a prion[0]. [0]:https://en.wikipedia.org/wiki/Bovine_spongiform_encephalopathy https://en.wikipedia.org/wiki/Bovine_spongiform_encephalopat...
  - mirimir 8y ago
    And it was spread by the livestock industry.
sandworm101 8y ago
It is also an are where our innate fears, fears that modern society tells us are unacceptable, might have a place. There is a deep-seated fear of diseased people that once kept us healthy. Modern science has given us an understanding of disease that means there is often no need to physically separate paints where we know the disease is not easily transmitted. The shunning of an aids victim, or a child with cancer, is totally unacceptable in polite society. But prions, and especially research into possible links to various forms of dementia, suggest some dark futures. Maybe it isn't a great idea for the kids to visit grandma in hospital.
- whiddershins 8y ago
  Nitpick note: The phrase is actually “deep seated.”
  - sandworm101 8y ago
    You are correct. I've heard it both ways and ascribed slightly different meanings, but deep-seated was what I meant.
  - 0db532a0 8y ago
    Oxford, Cambridge and Merriam-Webster say no.
    - nkurz 8y ago
      Why do you say this? And why phrase it so tersely? Merriam-Webster at least (the only one I've checked) says that "deep-seated" is the only correct version: Definition of deep-seated 1 : situated far below the surface 2 : firmly established https://www.merriam-webster.com/dictionary/deep-seated “deep-seeded” The word you've entered isn't in the dictionary. https://www.merriam-webster.com/dictionary/deep-seeded
      - 0db532a0 8y ago
        I was trying to make it clear that whiddershins was wrong to say that ‘deep seated’ is the correct usage in contrast to ‘deep-seated’ when Oxford, Cambridge and Merriam-Webster say that ‘deep-seated’ is indeed a correct usage. P.S. Inconsistency: I assumed that whiddershins was complaining about the hyphen, rather than correcting ‘seeded’, which had been changed to ‘seated’ by the time I first saw it.
mattmaroon 8y ago
I don't think that's true. Prions aren't bacteria or viruses that evolve and transmit. They're mostly just a misfolded protein that occurs spontaneously. (They can then be transmitted.) I'm not sure there will ever be a prion that hasn't already existed, whereas I am sure there will be new viruses and bacteria.
- wetpaws 8y ago
  With the same effect I can argue that viruses and bacteria are just misarranged RNA :)
- darpa_escapee 8y ago
  If they can replicate imperfectly, they're subject that evolutionary processes.
  - dahfizz 8y ago
    They don't replicate. Prions can't themselves make more prions like viruses do.
    - mattmaroon 8y ago
      I think the main difference is an imperfectly-replicated virus or bacteria might still be viable. A prion only makes itself. Even if it replicated imperfectly, the odds of a slightly different misfolded protein becoming another prion are vanishingly small (otherwise we'd all be dead) because there probably just are very, very few configurations possible. The vast majority of misfolded proteins just do nothing. There are several billion humans who are each replicating millions of copies of each of the 20,000 or so proteins during their lifetimes. It seems pretty unlikely that there are many misfolds that haven't occurred. It's just that only a handful become prions. And even if they do, prions are thankfully very hard to communicate (again, we'd all be dead if they weren't).
    - thfuran 8y ago
      They can induce correctly-folded proteins to misfold, effectively replicating.
greglindahl 8y ago
Is there someone advocating that we don't take measures now? Because we do take measures now. Example: there are a bunch of rules about what you can feed cows, and how to keep their nervous tissues out of meat at slaughter time.
dingby 8y ago
Your “next prion disease” is entirely hypothetical. Given that, it is pure speculation how to prevent its transmission. Why would you assume specific precautions taken would apply?
- travisoneill1 8y ago
  The same way standard protocols are used to prevent transmission of viruses & bacteria. Apparently they don't work on prions: > In a particularly vexing twist, prions are also nearly impervious to destruction, even when attacked using a strenuous combination of disinfectants, heat, and pressure.
Retra 8y ago
The fear may be rational, but the response to it needs to be rational as well. That means treating the things that are known to do the most damage currently, while maintaining containment procedures that can handle your black swan epidemics.

sillypuddy 8y ago

Is alzheimers a prion disease, or maybe just Prions are involved?

tshannon 8y ago
I believe Alzheimers is recognized as a metabolic disease now (some have even said Type 3 diabetes). It's in no way related to Prions.
- dingby 8y ago
  The diabetes/metabolic theory was one pitched theory, and it isn’t even a terribly mainstream one. There is no consensus that Alzheimer’s is a “metabolic disease”. Even thought ApoE is implicated, that association could be explained by numerous mechanism, even viral.
  - tshannon 8y ago
    Thanks for clarifying. I'm no expert just passing on things I've read. Regardless, it's unrelated to prions.
- jelling 8y ago
  No expert, but the latest studies have been about the correlation with the herpes virus and how the plaque build-ups that are part of Alzheimer's may be the immune system's attempt to protect the brain.
adamb 8y ago
My understanding is that there is some evidence that Alzheimer's is transmissible (e.g. higher rate of incidence in caregivers and neurosurgeons), but more study is needed.
- Fomite 8y ago
  There's also been observations of particularly large amounts of certain human herpes viruses in the brains of Alzheimer's patients.

CompelTechnic 8y ago

The article does a good job of mentioning small likelihoods but large stakes, and is intellectually honest in doing so.

davemp 8y ago

> This article is one good step above scare-mongering, but only one. I agree. Could a moderator please change the title at the least? "Prions, A Rare and Lethal Infection, ..." would be slightly better.

davemp 8y ago
In lue of the downvotes, would anyone like to defend the efficacy of the article's title?

ouid 8y ago

There is a great hypothesis that I remember my dad telling me recently, although I can't remember where he heard it from, that the reason that prion disease is so rare in humans is because we're, historically, very cannibalistic, so resistance to prions was heavily selected for.

subroutine 8y ago
The very opposite of this hypothesis is actually more likely to be true. Kuru is a manifestation of this same prion disease (PRNP gene variant disease) that is essentially only found in people from New Guinea who practiced a form of cannibalism in which they ate the brains of dead people as part of a funeral ritual.
- ouid 8y ago
  This is exactly the wrong interpretation. We know that cannibalism causes prion disease, and we have known that for as long as we have known about prion disease. the question is not whether cannibalism causes prion disease, which it definitely does, but whether past cannibalism was common enough to have selected for some innate resistance to it. http://www.virology.ws/2015/06/12/resistance-to-prion-disease-in-humans/ http://www.virology.ws/2015/06/12/resistance-to-prion-diseas...
  - subroutine 8y ago
    Like you said, we know that cannibalism causes prion disease. We know this. Thus, we are not resistant to it. So from an evolutionary perspective you could make a strong argument that what actually happened was that those humans who didn't engage in cannibalism and die of prion disease were heavily selected for. Which is probably why you don't see many humans eating the dead. Now that last bit is speculation, but all this is speculation. But based on my own introspection, I'm imagining myself stumbling upon a recently dead human corpse, I'm almost certain my innate reaction -- (well, almost surely innate, and not socialized, since I've never been explicitly taught how to react in such a situation) -- is that I'm definitely not going to fucking eat that corpse. In fact, the only humans that do seem to still engage in cannibalism do it out of some social ritual.

g3cko_ 8y ago

An incidence of 1 per 1,000,000 may not seem that scary, what are the odds of knowing someone who gets CJD? Obviously, much greater.

bimr 8y ago

On the contrary, this falls within Nassim Taleb's Minority Rule. Prions, being nearly indestructable, are an intransigent minority that will eventually hold sway over the rest of us. Many on this board point to the inelasticity of their transmissible potential and call this fear-mongering. However, it is that same inelasticity that makes them intransigent. Once they have compromised an instrument, that instrument will remain compromised until each prion has specifically been destroyed. When you pair that intransigence with its lengthy incubation period, you actually have a force multiplier that, while not viral, would be scary enough to change behavior. Fortunately, the article hints that retinal scans may eventually be used for initial diagnosis.

Terr_ 8y ago

> Prion disease is exceedingly rare. Isn't that begging the question? I mean, the author's concern seems to be that the prevailing belief hasn't been well-tested compared to the potential impact of it being wrong. It's already happened before: There was a period of time when most medical practitioners were adamant that their actions could possibly be transferring disease, and it was an uphill fight to get regular disinfectants and hand-washing.