In the UK, the Food Standards Authority (FSA) has just come up with the idea of banning sheep gut as sausage skins. This is to reduce, by 25% apparently (how do they work that out?), the theoretical (FSA’s own assessment) chance of contracting vCJD through the theoretical (FSA’s own assessment again) possibility that sheep are already harbouring BSE. Putting aside the ludicrous chain of improbability constructed by the FSA, does anybody know what studies have been done proving (as opposed to “suggest”, “may”, “might”) that a link between BSE (which infected millions of cattle), vCJD (which has killed 73 people in six or so years) and sheep (no evidence of BSE yet discovered) exists?
This is the Food Standards Agency’s own explanation, including details of the studies on which their recommendation was based.
Sadly, it’s just a waffly summary, with no supporting data other than a study which uses a range of estimates, plucked out of the air, and then builds a case. As science, it’s crap. No data = no conclusion, but that doesn’t stop them. The FSA starts off by stating that they are making no recommendations to reduce consumption but then argues that sheep gut should not be used as sausage skins. Surely that’s a recommendation?
It looks to me from the link APB provided that ther is no evidence linking BSE to sheep. Indeed, the whole thing seems to be talking about ‘theoretical’ risks. While they’ve found no BSE in sheep they claim their testing methods aren’t refined enough to categorically state that BSE can’t exist in sheep. The possibility for sheep to be merely exposed to BSE seems reasonable so this report is merely telling consumers to make an educated decision.
It seems that this is one of those things that should people ever become infected via eating sheep they’ll go nuts screaming why the food agencies didn’t warn anybody. So, to help deflect any future criticism, the FSA says, “We don’t know anything but it’s your choise what you eat so don’t blame us if anything goes wrong down the road.”
(Some redundant info, upon preview.)
http://www.newscientist.com/hottopics/bse/bse.jsp?id=ns99991772
The BSE in cattle was apparently spread in the feed, and was also fed to sheep. The problem they’re having is determining if the sheep have it, as it closely resembles scabies.
From the article:
and:
So it’s more a matter of being safe than sorry until they can determine for sure if the sheep were infected, I think.
I appreciate Whack-a-mole’s point in that the FSA is doing a bit of arse covering. However, if the intention is to give people enough data to make an informed decision, they negate it by proposing a ban on sheep gut sausage skins to reduce the risk. That implies the FSA knows something we don’t, otherwise why would they want the ban given the astronomically remote chance of any body contracting vCJD from BSE infected sheep?
I apologise for sounding a bit of a bore on this. I’m still looking for any data that prove a link between vCJD & BSE.
This is just a WAG on my part so don’t crucify me if I’m way off base here.
I would guess the deal with the sheep’s intestines being specifically pointed out has to do with how a sheep is likely to get BSE. If the sheep is exposed via eating sheep chow made from cow brains then the BSE will travel through the sheep’s gut. Even if the sheep itself doesn’t contract BSE I suppose it is possible that some BSE ‘residue’ can be present in the intestine. I have no idea what cleaning measures are taken in processing sheep gut for sausages but perhaps it is possible that whatever they do isn’t sufficient to be certain the intestine is sterilized. Presumably, then, a human could contract BSE from sheep in this fashion even though the sheep itself isn’t technically infected.
Don’t take offence but…
I think you’re missing the point. The mechanism described by the FSA is all “might be”, “may be”, “possibly”, etc. I am not disagreeing with your theories per se nor necessarily with the FSA’s. The problem I have is the complete lack of any hard data to support them. That’s not your problem, you don’t profess to be an authority on food and health safety, but it is the FSA’s.
The purpose of my original post was to track down the hard data. I suspect that there isn’t any but, as they say, “absence of evidence isn’t evidence of absence”.
Does this mean that you won’t be able to get a proper haggis in the future? :eek:
Well…I guess it is as I mentioned before but you put more eloquently.
“…the FSA is doing a bit of arse covering.”
I meant to mention this in my earlier post but hit submit too soon.
I think you won’t find the evidence you are looking for. The FSA itself is upfront in saying that this is all theoretical. They have no evidence linking sheep as a vehicle for transmission of BSE. However, they also state that their tests aren’t up to the task of ruling out sheep as a transmission vehicle either. Given that they think the odds of sheep having been exposed to BSE in sheep chow or other means are better than even the FSA figures it is prudent to inform consumers of a potential threat so people can make up their own minds (and cover the FSA’a arse). Presumably the FSA will contuinue investigations into this issue but till then this is the best they can do.
I agree - there isn’t any to find. That’s not just the problem with the sheep-BSE link but also for the vCJD-BSE link.
I’m starting to sound like a broken record now 
I think I’ll go home now and have some beef sausages and haggis 
I agree - there isn’t any to find. That’s not just the problem with the sheep-BSE link but also for the vCJD-BSE link.
I’m starting to sound like a bit like a broken record
I think I’ll go home now and have some beef sausages and haggis
Bear in mind: there is no hard evidence for the existence of prions; while most people in the filed are coming around, the argument for their existence, and their role in BSE, is almost as thin and hand-waving as the article you cited. Remember also that the FSA is expected to give warnings and ban dangerous practices BEFORE a statistically analyzable number of cases have been reported. Given this, they are forced to use thought-experiments to assess the dangers of infection.
Vogue vixen: "The BSE in cattle was apparently spread in the feed, and was also fed to sheep. The problem they’re having is determining if the sheep have it, as it closely resembles scabies. "
I believe you meant “scrapie”.
Scrapie is so called because the sheep “scrape” themselves --I reckon, sort of like compulsive scratching until they wear through their skin. BSE is said to “closely resemble” scrapie because scrapie is spongiform encephalopathy in sheep, where as BSE is spongiform encephalopathy in cattle. NVCJD is spongiform encephalopathy in humans.
The theory (as I gather) is that “rendered” sheep, especially sheep that rendered themselves unsaleable to consumers via scrapie, were made into cattle feed and that their disease eventually jumped the “species gap” into cattle. This was facilitated by the frequent use of rendered sheep material as cattle feed; exposing the cattle more often gave the prions or whatever a much higher chance to adapt itself to cattle than would have been the case if (say) sheep and cattle just sort of hung out together on the same farm. Similarly, people who eat a lot of beef supposedly expose themselves to a similar prion jump into the human species. It appears that there are also other factors that make a specific member of a species more receptive, such as (possibly) genetic predisposition.
I don’t know about the skeptisim expressed in this thread… I get Medscape’s Neurology e-mailed to me weekly, and their sources don’t seem to regard this as some far-out, crackpot theory. There is clearly a lot that isn’t known about BSE/NVCJD, but it seems to me that some caution is warranted.
If memory serves me right, per Medscape Poland and Italy both have recently had cases of NVCJD (human SE) following cases of BSE (cattle SE). China has banned import of cosmetic products made from cattle until such time as the sources can prove the products come from cattle known not to be contaminated (this of course favors US manufacturers). The EU seems to now want to test all beef flesh for contamination, being of the opinion that it isn’t just neural tissue that can harbor the prions. Here in the USA, we have a case os NVCJD that authorities are very quick to point out is in a relatively recently arrived British young woman.
Supposedly, we don’t have any animal SE here in the USA. At least in domestic animals… there IS CWD (Chronic Wasting Disease) in deer, elk, etc. and it has been around for a while now. AFAIK, such animals aren’t “rendered” into cattle feed, and though in some western states cattle share land with these animals, the expanses render exposure limited at best. I hope.
As far as I know, the facts are as follows:
Sheep get scrapie (hundreds of thousands per year)
Cattle get BSE (used to be hundreds of thousands per year)
Both are spongiform encephalopathies.
Sheep were rendered into cattle feed.
Cattle were rendered into cattle feed.
MIllions of people have eaten scrapie infected sheep and BSE infected cattle.
People get CJD (tens per year)
People get nvCJD (tens per decade)
Both are spongiform encephalopathies.
The method of inter and intra specific cross infection is unproven.
My conclusion, for what it’s worth: Something doesn’t add up.
I believe Prusiner (sp?) has already got his Nobel Laureate for prion theory, even though none have been linked to BSE infected cattle, scrapie infected sheep and CJD infected people.
This is possibly why as Go Alien said “Something doesn’t add up”:
CJD has likely only shown up in 10 or so people a year (despite the fact that many thousands of people have consumed BSE-tainted meat) because it takes humans 10-30 years to incubate the CJD/BSE prions.
So, it still could become an epidemic.
Ah yes, incubation period. Call me an old cynic, but…
I have also seen the figure The Great Dalmuti quotes. It’s used fairly liberally in lots of places but I don’t know where it comes from.
First of all - the disease linked to BSE is said to be vCJD, of which we have a handful of cases a year, typically younger people.
Let’s assume that there is no link. Therefore vCJD is a disease that is either new or is only now being correctly diagnosed. It has a very low rate of occurrance in the general population - less than a hundred people in an adult population of over 40,000,000 in the UK in about six years.
Now let’s assume there is a link. Because we have assumed a link, we now have to explain why there are so few cases for such a large beef eating population. To get any sort of epidemiological profile that fits the data, we have to assume it’s the tip of the iceberg. So the disease has to have a highly variable incubation period with extreme limits to account for the observed low number of cases so far agaisnt the assumed level of infection. By assuming the link, the variable incubation period has to be the reason there are so few cases and, conveniently, having justified the long incubation period (now regarded as a “fact”), we can now account for the low number of cases. Everything stems from the assumed link, which is still unproven.
We have no real idea what the incubation period is, just a guess to fit the initial assumption and the actual data.
Besides, in the UK there have been cases of lifelong vegetarians contracting vCJD. So how did they get infected? 
Go alien said that:
in the UK there have been cases of lifelong vegetarians contracting vCJD.
Do you have a cite or a link to this information? I’m afraid I haven’t heard of this.
Also, several scientists are studying the possibility of transmission through common innoculations such as Hepatitis A Vaccine, etc. as they are based in animal by-products.
Other products by which transmission possibly could occur are as follows:
vitamins or medicines made with gelatin capsules, vitamins including animal by-products (for example calcium derived from bovine bone), and rendered skimmed animal fat used in some common cosmetics and topical medicines (especially those medicines applied to open wounds on the body and so could be directly introduced into the blood stream).
There is also the possibility that a chef could cut meat at a restaurant, then use the same knife to cut vegetables. The vegetarian eats the vegetables with the infected prions and becomes infected.
Really, we all know nothing about CJD or BSE.
So, it is possible that a vegetarian who still uses some animal products could contract the disease.
Epidemic? Here are Monthly new variant Creutzfeldt-Jakob Disease Satistics from 2 Apr 2002
1990 -
1991 -
1992 -
1993 -
1994 -
1995 3
1996 10
1997 10
1998 18
1999 15
2000 28
2001 20
2002* 6
*As of 28 Mar 2002
Looks too early to call.