I was reading an online article on Mad Cow Disease and it firmly establishes a connection on the cause being a prion.
I was wondering what the debate in the scientific community is on this? Is it pretty much accepted that prions can cause disease? Or is it something that is still up in the air?
http://www.cdc.gov/ncidod/dvrd/prions/
Note that the brain normally contains prions, but in these diseases, one prion becomes altered and becomes a template for other altered prions: Prion - Wikipedia
Recently, I asked Stanley Prusiner this question. The theory used to be very controversial, but ultimately Prusiner won the Nobel Prize, which is a pretty good sign that it is widely accepted. I asked something like, “Is it still controversial? Are there still people who don’t believe it?” He shook his head and said “No.” Then, after a pause, he said, “Well, of course, some people will go to their death refusing to believe in it,” or words to that effect.
I think it is pretty well settled.
Yes, pretty well settled. Diagnosis for many different prion diseases (Mad Cow is not the only one) depends on identification of the specific prion protein either by its bands in Western Blot, or in affected areas (and occasionally lymph nodes) by positive immunohistochemistry against the prion protein.
I know some guys in a prion lab on campus. As has been said, it’s pretty well established that prions exist and that they cause disease. There’s not much argument about that.
The biggest question right now (at least in these guys’ minds) is whether prions fold spontaneously in isolation or require some sort of cofactor to help the process along. Experiments seem to show that they CAN form by themselves (although it’s nearly impossible to completely rule out contamination), but they also show that they form much more readily when certain other molecules are included in solution. Generally, from what I’ve heard, long anionic molecules, like RNA, work best. It’s unclear what actually happens in vivo.
These diseases are truly horrifying and there ought to be far more research into solving them. On top of Mad Cow, there’s also Mad Deer (CWD) and even Mad Squirrel disease, all of them caused by prions - and it’s my belief that it all started with inhumane factory farming, cannibalistic cattle feed, and the slaughtering of sick animals. The prions get into the cows; the prions (since they cannot be killed) remain in the cow manure, which then seeps into the water table and gets into the soil and the groundwater. Deer, then, get it. It runs off into waterways, then even fish get it (there have been studies showing that fish can get prion diseases.) It’s a disaster, and it is all caused by human incompetence in farming practices.
Much of what Argent Towers said about how the Mad Cow Disease (BSE) was originally spread is true. However, it is no longer legal to feed cattle parts to cattle. Cattle farmers fear not only the law, but having to destroy their entire herd if one cow is diseased.
The prions are found only in the brain and spinal cord. The rest of a diseased animal is safe to eat. Even so, it is now illegal to butcher a “downer” animal, that is, a cow that cannot stand up. It has been several years since the last case of BSE in the United States.
How much research do YOU think should be done? Do you know how much is being done at the moment?
Prion diseases have been around since antiquity. Sheep scrapie, the classic prion disease, has been known for centuries, at least. Deer prion disease has also been around forever. The practices to which you refer were certainly major contributing factors to the spread of vCJD, but the existence of prions is due to an intrinsic feature of the protein.
Seconding what Smeghead said. Scrapie, THE prototype for prion diseases, has been known for centuries, and not only that, but it is NOT considered transmissible to humans. Chronic Wasting Disease (CWD) behaves similarly to scrapie. While I’m not sure what the origin is, one of the concerns for deer farms is the possibility of transmission between wild and domestic herds (and loss of revenue from infected animals), or between deer and cattle.
AskNott, IIRC, it has been illegal for years to slaughter a downer cow, even before the first suspected BSE cow was found in the US. In fact, I’m not sure if that was one of the reasons why they found the case (the cow was down, they decided to test the brain). After all, there are other more compelling reasons why not to slaughter a downer cow.
BSE, at least the variant that causes Mad Cow disease, and a couple of other prion diseases in other species (including IIRC humans and minks) are considered to be more food-borne diseases. Other prion diseases are not like that. You cannot blame human farming practices for all of them.
Argent, as I told you in an earlier thread, just because the media is not reporting it, this doesn’t mean that prion diseases are NOT being studied. Believe me, they are. As I’m about to take my specialty boards, I’ve had to read plenty of articles about them published in the last few years. And I know I’m just touching the surface because there are many more articles that deal with other aspects of the disease that are not my focus area. Prion diseases are certainly a hot topic.
Just because a horrifying disease has no cure doesn’t mean nothing is being done to study it. In the last 10 years, over 10,358 articles have been published on prions, with almost 8,000 of those on prion diseases.
This research is well-respected, as evidenced by Stanley Prusiner’ Nobel Prize in 1997 for prion research.
This research is increasing. In the first 5 years after Prusiner discovered prions, there were 264 articles on prions. In the succeeding 5 year periods, there were 526, 1551, 2687, and 4152 articles published, a very active trend.
This research is funded and supported by national resources. The National Institutes of Medicine has a National Prion Research Program. The U.S spends $3.5 million in epidemiology and surveillance alone, for what is literally a one in a million disease. That’s $13,672 for every new case of CJD found. Since 2002, Congress has given the USDA’s Animal and Plant Health Inspection Service funding specifically for prion diseases, to the tune of $15million. The CDC and NIH also fund prion research as do a number of private foundations.
Clearly, there is a lot of work being done. Given the infinitesimal rarity of prion disease in humans, this doesn’t suggest ignorance by either the scientific establishment or the government.
Just to re-iterate what others have said, this is a completely inaccurate statement. Prion diseases far predate industrialized farming. Kuru was discovered in the 1950’s, but has been established to date back to at least 1900. Gerstmann–Sträussler–Scheinker syndrome was identified in 1936. Sporadic and familial Creutzfeldt–Jakob disease were also described in the 1930’s. The first recorded victim of Fatal Familial Insomniadied in 1765. Scrapie has been known since 1732. Factory farms did not create any of these.
I don’t believe it’s a completely inaccurate statement.
While it’s true that prion diseases existed before the introduction of factory farming, the farming practices used - including feeding rendered carcasses back to cattle - opened up a vector that was far more likely to cause the spread of non-human prion diseases through both domesticated animals and humans.
Sporadic and familial CJD and FFI are terrifying enough, but at least there’s a family history there. Don’t want Kuru? Don’t kill your enemy and then eat his brain.
But vCJD is a much different beast. Unless you’ve been a strict vegan your entire life, you stand a chance of being exposed to the cause through your diet.
It’s great that we don’t feed rendered cattle carcasses back to cattle herds, but it’s still legal to feed cattle any other animal by-product - like rendered turkey or chicken carcasses. The rendered cattle by-products just get used in something else - like feeding pigs or pets. So, we still have the opportunity of cross-species prion infection into the food supply, and we still don’t dispose of slaughter waste in a manner that would prevent prions from entering the food chain from another direction. (Thermal depolymerization is a process which can destroy prion molecules.)
We’ve been playing Russian Roulette with our food supply in more than one way. This just happens to be one of the scarier ones. Prion diseases are nightmares, like Alzheimers on steroids. The chances of transmission may be minuscule, but over the years, with more and more factory farming and a push for de-regulation, the odds are going to add up.
Yes. I couldn’t have said it better myself.
Someone correct me if I’m wrong, but this is what I understand to be true of what can happen to animal waste:
Rendered cattle carcasses can be fed to chickens or pigs.
Then the remains of these chickens or pigs can still be fed back to cows.
This means that not only can cows still get the prions, we can also get them by eating pork and chicken. The prions can get into pig and poultry feed. Right?
Then, when animal carcasses of all kinds are disposed of, prions can leech into the soil and ultimately into the water.
I’ve also read that dead dogs and cats are rendered and find their way into certain types of animal feed (truly disgusting.)
Our greedy, obsessive quest to extract every single bit of money from our food animals has brought this horrible situation upon us.
Wrong? Can you provide any evidence whatsoever that BSE has been transmitted in this fashion?
The statement was:
(emphasis added)
That statement is flatly inaccurate. Prion diseases did not all start with factory farming and BSE is the only one that has any connection to farming practices. The other diseases mentioned have no link to factory farming. I’d really like to see some scientist try to tie factory farming to encephalopathy in squirrels.
Just as a nitpick, phouka, I believe kuru was transmitted through funeral practices for family members, not enemies.
Isn’t this just common sense? A prion is a virtually indestructible particle that is assimilated by eating. You have a cow with prions, you grind that cow up and feed him to chickens, then the chickens get the prions…you feed those chickens to other cows, then the cows get the prions…people eat those cows, then the people get the prions. Prion laced meat is eaten by wild animals, then shitted out, and the prions from the shit leech into the water and soil. Or squirrels eat the shit.
“Just common sense” is not an empirical argument. It’s armchair theorizing at best. Find one cite that shows any connection between domestic animal husbandry and wild prion diseases.
Okay.
Here’s the CDC on Chronic Wasting Disease:
From The New Scientist:
And we have from The National Institutes of Health abstract of a paper published in The Lancet
So, we have three competing theories:
New variant CJD is caused by eating beef tainted with prions from cattle infected with Bovine Spongiform Encephalopathy. The cattle were, in turn, infected when fed rendered by-products of sheep infected with scrapie, also a prion disease. This was made worse when cattle were also fed rendered by-products of other cattle now infected with BSE.
New variant CJD is caused by eating beef tainted with prions from BSE, but the BSE was caused by a spontaneous gene mutation. The reason it became a problem was because the cattle were fed rendered by-product of at least one individual bovine with the genetic form of BSE. It then became an acquired form, not unlike Kuru (though, admittedly, the cattle were more likely to be eating their ancestors than their enemies).
We caused this particular form and outbreak of BSE when rendered animal by-products from India contained some human remains of a person with CJD were imported into England and other EU nations and fed to cattle.
Now, unlike Argent Towers, I’m not claiming prion diseases were caused by factory farming. I have no problem accepting epidemiological evidence pointing at prion diseases existing for far longer than Industrialization or even, in the case of Kuru, agriculture. I also haven’t a word to say about squirrels, other than I find them untrustworthy. It’s just that before factory farming, prion diseases in livestock, while bad, was several orders of magnitude smaller a problem.
We have first hand evidence of cow-to-human transmission of prion disease in the US, Great Britain, France, and Ireland, among others. Therefore, prion diseases can be transmitted from one mammalian species to another, even when the species belong to different orders.
That version could only be transmitted when the person ingested infected tissue - and the CDC says it’s not just brain and CNS tissue to be worried about. It warns hunters not to eat any spleen, lymph node, or peripheral nervous tissues and also pretty much comes out and says the prions are present in all tissues. Yet, there’s another prion disease - Chronic Wasting Disease - that is apparently transferred environmentally. Both wild and farmed deer have tested positive for it.
We also understand, that prions cannot be destroyed by cooking or by normal environmental degradation. Therefore, prions can contaminate open and near-ground surface water. The World Health Organization’s recommendation for prion sterilization is a combination of submersion in a bleach solution for an hour and then another hour in a super-heated autoclave. The only other process I’ve read about that can reliably destroy prions is thermal depolymerisation, which I linked to earlier.
Now, maybe, we can get away with feeding rendered birds to mammals, rendered mammals to birds, and prion diseases won’t be able to cross classes, even though they can cross orders. I don’t think it’s wise.
But we still feed rendered mammals to other mammals, and those mammals back to the first group of mammals, and we know that prion diseases can cross from ungulates to primates. The jump from porcine to bovine is a lot smaller.
It’s not that factory farming conditions caused prion diseases in domesticated animals. It’s that the conditions of factory farming - unbelievable crowding, keeping animals in pens knee deep in their own wastes, early slaughter ages, and feeding them flesh when they evolved as grazers - is the epidemiological equivalent of walking naked through a crime-infested neighborhood while the police are on strike and telling people that you have $100 bills in your vagina only reachable by a long enough penis. Something Very Bad is going to happen to you.
What if BSE were to mutate and become transmissible by saliva or droppings? [Answer: beef is permanently off the table for most folk, and a whole bunch more people are going to be cerebral swiss cheese.]
What if the incubation period became longer? So that when an infected beef went to the slaughterhouse, it had no symptoms at all, but was just teeming with prions? [Answer: a whole lot more people are going to be cerebral swiss cheese, since the only way to reliably test for BSE is to look at brain tissue under a microscope. And beef is probably not what’s for dinner ever again. Unless it’s really, really old, really, really expensive beef.]
What if BSE were to jump from cows to pigs, creating another vector? [Answer: say goodbye to bacon, porkchops, sausages, and ribs. Say hello to your friendly neighborhood zombie hospice center.]
What if BSE became even more epizootic and jumped from cows to birds? [Answer: well, shit, I guess we all just became vegans.]
What kills me is that there’s a very simple answer to this issue:
Stop feeding animals to the animals we eat.
I’m not thrilled with factory farming anyways. Jeez, feeding cattle on a diet of corn instead of grass is pretty much the reason we have e coli everywhere, antibiotic resistance out the wazoo, and the world’s highest rate of heart disease. But considering that we could go from that to “anyone who’s eaten any beef or pork in the last five years, please report to the zombie room” without much warning at all, makes the first option downright warm and fuzzy.
Animal slaughter products should not be fed to our food. We’ve got a perfectly good way to turn it into fuel without even increasing our greenhouse gas emissions. We just have to be willing to tell the big agricorp businesses that they don’t get to play their little cannibal games anymore.
A fine nit, sir. I remember watching a documentary where eating of the vanquished enemy was mentioned as a way of absorbing the enemy’s prowess. Eating of the dead family members was also mentioned.
Of course, from the choice family psychodramas I’ve seen, there’s no reason to believe the two groups are mutually exclusive.
IIRC this is wrong. The prion is the altered protein. In it’s normal state it is not a prion, but can be turned into one by another prion.
This seems absurdly unlikely. Prions are litre bits of protein. How are they going to filter down through the soil and rock into groundwater?
If you’re talking about farming runoff into rivers, that’s a different matter, but also causes gastric diseases, which is why drinking water is treated on its way to us. Aren’t prions destroyed by chlorination?