New info on Chronic Wasting Disease

[M77Fan]

Pertinent to cleaning equipment after field dressing, cutting up, and/or butchering game, below is the reference to the original study that led to the bleach bath Noobie mentioned. That study recommended the use of household bleach to clean knives, saws, butcher equipment parts, etc.. It goes into the methodology of the study and is a technical paper, but the gist is that household bleach can denature prions when they are out and exposed to treatment. This just applies to equipment and tools. There is nothing in the literature so far on denaturing or neutralizing prions in meat, and more to the point in brain or spinal tissue.

Quoted below is a statement with their findings. It should be noted that the bleach can't deactivate prions inside solid meat during the 5 minute soak, but a thorough scrubbing via conventional washing ought to remove meat bits from tools and equipment. Their experimental method called for painting prions onto stainless steel equipment parts, and allowing the material to dry, before treating with sodium hypochlorite; a realistic situation for equipment as you process, and as meat bits dry onto cutters and blades as you proceed.

This procedure would also address any bacteria or viruses that might be involved as well.

From "Inactivation of chronic wasting disease prions using sodium hypochlorite"
Published online 2019 Oct 4. doi: 10.1371/journal.pone.0223659

The study report can found at the link below.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6777796/

"First, we tested bleach against CWD-infected brain homogenate solutions to quantify levels of prion inactivation. Second, we tried to mimic two scenarios that could occur in the field and/or in game processing. Stainless steel wires were coated with CWD prions and dried to simulate how prions may adhere to knives, saws and other equipment. We also tested small pieces of whole CWD-infected tissues to see how effective bleach may be against residual bits of tissues remaining on contaminated equipment. Our data showed that strong concentrations (40%) of household bleach for a minimum of 5 minutes is effective at inactivating CWD prion seeding activity from stainless steel surfaces and brain homogenates. However, tissue penetration of bleach was poor and attempts to inactivate CWD from solid pieces of brain were not successful."

Getting back to field handling, the recommendation is to bone out the meat, and to leave the brain, spinal column and remaining and skeleton behind. If you take the head or just take the skullplate, presumably you would use a saw to separate it. That should be done after all the meat is removed and stored/removed from the work area, and that saw should not be used in association with any meat handling since it could be contaminated with infected brain matter if the animal did actually have CWD. Saws used in this manner should be isolated from meat handling, and should also be decontaminated with bleach soaks. If you use a knife to disjoint the skull, the same precautions should apply. Do that last, and disinfect your knife afterward. Using different knives for different deer (or elk/moose), especially if you have no way to do this disinfection, is also prudent to avoid cross contamination from one animal to another, should CWD be present in one of them.

Keeping the meat of each animal separated from any others also is a good idea all the way through packaging. That way you don't co-mingle the meat of different animals in case you have one positive. If kept separate and marked, you would only need to dispose of one not all.

Hope this helps those wondering about this part.

 

[Old Rooster]

M77Fan that was very informative and I will keep this reminder as I plan on copying and paste to Jarte and keep it.
Thanks for all that research.

 

[Noobie]

Be careful there are some guys on here with really tight Sitka jeans who are going to call you a conspiracy theorist and talk about tinfoil.

Don't label me conspiracy theorist, based on my tight Sitka pants, please. But I do need some new conspiracy theories, because all my old ones came true.

Actually, prions were initially considered to be a conspiracy theory in the scientific community:
The word itself derives from 'proteinaceous infectious particle'; it refers to the initially heretical hypothesis that the infectious agent causing those diseases consists only of protein, with no nucleic acid genome.
Quoted from an article that puts forth several takes on the current scientific 'consensus'. I almost missed the last summary because it follows a large 'related stories' section.
The molecular structure of prions and how they cause infections like Creutzfeldt-Jakob disease
It also explains why such things as UV light are not effective against it. Apparently some forms are inherited in humans.

 

[Old Rooster]

I sure have learned a lot!Thanks to all that have informed us with backable data.

 

[M77Fan]

OK, this is really long, but this lengthy thread of facts and opinions has been bugging me.

This is a big gripe I have with current day "journalists". So many of them just clip and copy bits of pieces of scientific articles (or any other news stories) to make their deadlines, and hopefully generate clicks on the basis of something sensational, scary, or outrageous. Most of them appear to have no understanding of the subject matter. As usual the first story from Old Rooster was one of these, though he did find a second one that reported a bit more sensibly on the subject. The fear mongering one was very shoddy reporting using plagiarism of several recent parroted articles, and an alarmist but actually false headline.

First a little information on Creutzfeldt-Jakob disease (CJD). Four types of CJD are known: Sporadic [spontaneous] (sCJD), familial or genetic (gCJD); iatrogenic [drug-related] (iCJD) and variant CJD (vCJD). The vCJD results from transmission of bovine spongiform encephalopathy (BSE), a brain and nervous system disease, that jumped from cattle to humans. The best known cases have occurred in association with people eating contaminated beef in the UK (mad cow disease). These are diagnosed from characteristic brain damage and when folded protein prions are found. At least one of the men discussed in the article was diagnosed with sporadic CJD, not the variant-type that is associated with the transmissible mad cow disease.

Chronic Wasting Disease (CWD) in deer and their relatives is a disease of the brain associated with malformed prions. This is the reason that most instructions for handling game from areas with known CWD require that heads (brains) and spinal cord as well as skeletons be left at the kill area, and only edible meat and cleaned skulls/skullplates be transported away. The exception being if the head is to be retained for testing. The game departments are trying to leave infectious materials where the infection was - in case the animal had CWD.

Almost all game departments now have regulations about transporting meat from an area with known CWD, and most states now also have regulations about transporting meat and other parts across state lines. This is a routine and common-sense contaminant control methodology. They also recommend using rubber gloves for field dressing and meat handling (not a bad idea generally), and having your animal tested. Testing requires bringing out the head so the lab can sample it, or extracting lymph nodes to submit for testing. Wyoming Game and Fish has good instructions available on extracting the lymph nodes. To avoid sample cross-contamination between deer, you should use separate knives, blades, or thoroughly clean equipment between samples collected. Also keep samples from each animal in separate containers. I personally process each animal entirely separately so I can isolate meat of an infected animal should I ever have one.

Getting back to what Old Rooster posted, if you follow it back, the report from the Texas neurologists/researchers speculated that the 2 men who died from Creutzfeldt-Jakob disease (CJD) and who belonged to the same hunting club might have died instead from CWD. They speculated it could have been CWD caused rather than CJD. But both were diagnosed as CJD, which means the medical examiner had to have done lab work to verify the cause of death. For CJD, this is normally done by microscopic examination of brain tissue looking for telltale lesions and damage. No specific discussion was made on what was used to diagnose the first victim. In the case of the second individual this tissue biopsy was done, and he was diagnosed with sporadic [spontaneous] CJD - which is not a transmissible form. The reporting leap was then that they had been eating CWD infected deer because CWD was known to exist within the deer population where they hunted. Maybe they actually had their deer tested and didn't eat any that were positive with CWD; there was no followup on that in the reporting.

Taking this on a different tack, what if the two guys were actually related? Not an unreasonable possibility with two guys in the same hunting club. If they were related could they have both inherited a tendency to develop gCJD because of heredity?

There was not any direct evidence presented that they had actually eaten CWD infected deer, nor that their infections were from the same source.

Although deer meat was clearly part of their diets, there was no statement on what else was regularly eaten by the two victims. Did they eat sweetbreads (brains) from sheep, goats, cattle? Eating brain material of "mad cows" has been connected to human cases of CJD.

There are 350 identified cases of CJD per year in the US, compared to a population of 333.3 million people, or 1 to 2 per million. These two cases were cited as a "cluster" in the paper, which is very far out there from being any sort of valid statistical cluster or trend. These were 2 people who hunted deer versus 11 million US deer hunters, or 0.0000181% of all deer hunters, that developed CJD for unknown reasons.

In Old Rooster's second cited article, the scientists at the National Prion Disease Pathology Surveillance Center and the Centers for Disease Control (CDC), which have been monitoring these types of illnesses for decades, weighed in and said that it is highly unlikely that venison or CWD had anything to do with the deaths of the two men. These guys are the experts on CJD human cases, which are very rare.

"We do not agree with the suggestion that these cases were caused by consumption of deer meat," said Ryan Maddox, a senior epidemiologist and deputy chief for the CDC. He said the agency reviewed both cases in 2022. "We feel strongly that they are part of the normal number of cases we see," he said. "Many Americans hunt and even more eat venison. Some will develop sporadic [Creutzfeldt-Jakob] by chance and others will not."

The majority of cases of CJD (about 85%) are believed to occur sporadically, caused by the spontaneous transformation of normal prion proteins into abnormal prions. This sporadic CJD occurs worldwide, including the US, at roughly 1 to 2 cases per 1 million population per year.

This is a lot like the original papers I have read, like that report on lead poisoning in eagles, etc.. I always try to find the source document. In that case, first there was sampling bias by someone with an axe to grind and a background of activism, then there were erroneous interpretations by readers (so called journalists) and those who cited the findings (without discussing how the evidence was derived), then off it went into advocating banning lead bullets. Maybe there is some basis in fact with all of this; lead will call organisms in high enough doses, but the "scientific approach" was suspect due to lack of actual true scientific method. The sampling of sick birds did show lead poisoning, but there did not appear to have been sampling of healthy birds that had also been scavenging. Further, many of the sick and dead birds had been feeding habitually at landfills and on roadkill. They were not even out in the hunting fields where the authors were claiming raptors were being poisoned. The sampling appeared to be opportunistic data gathering on sic and dead birds – without a solid sample design beforehand. But since the press picked it up, now it is cast in stone.

Sorry my scientific background, and participation in studies that were later used to try to force statistics to say things they couldn't has made me very skeptical of the lack of true scientific method in many such reports.

That sensational reporting ought to cause panic all over the nation.

Although I do know of some people who consumed part of a deer that later tested CWD-positive, and they did not suffer ill effects (to date), I remain cautious. It is still a possibility that there could be transmittal. I hunt in an area where a couple deer tested positive a number of years ago, which is why we get every deer tested for CWD before consuming any. Personally, I don't want to be first.