GardenBanter.co.uk

GardenBanter.co.uk (https://www.gardenbanter.co.uk/)
-   Gardening (https://www.gardenbanter.co.uk/gardening/)
-   -   Bone/ Blood Meal and Mad Cow Disease (https://www.gardenbanter.co.uk/gardening/62344-bone-blood-meal-mad-cow-disease.html)

Bill Oliver 02-06-2004 01:09 AM

Bone/ Blood Meal and Mad Cow Disease
 
In article ,
paghat wrote:

Your usual netkook thinking at work again. Someone could jump off a cliff
& break his spine & cave in his skull, & if it were profitable to convince
others to break their spines & skulls, you'd tell 'em the headlong leap
was harmless, because all the injured parties were actually maimed &
killed because they breathed air & drank water water & wore clothes.


No, paghat, that's what *you* are claiming. Here's a clue again --
association != causation. The "netkook" thinking is to inflate
theoretical risks into something they are not. Yet one more clue,
Paghat. There's a reason it's not called "beef renderer's disease."

Tell me, Paghat, how many British meat renderers have contracted
BSE? After you tell me that, tell me how risky casual contact
is. Your "netkook" hysteria is the kind of thing that made people
afraid to touch HIV positive patients.

There are risks, but people should find out exactly what they are,
not inflate fantastical risks from their ideology.

billo

Ermalina 02-06-2004 02:02 AM

Bone/ Blood Meal and Mad Cow Disease
 
Bill Oliver wrote:

In article ,
Janet Baraclough.. wrote:

There is another way to contract nv CJD, via human blood products and
contaminated surgical instruments, which may explain why vegetarians
also develop the disease.

Janet.


Please provide a citation of a case of BSE/vCJD transmitted by blood transfusion.
Blood transfusion is an inefficient method of transmission in sheep, and as
far as I know, there has never been a case in humans. If you have a case,
please cite it.

More important, please cite the actual calculated risk (for example, see:
Dealler S. Transfus Med. 1996 Sep;6(3):217-22 A matter for debate: the risk
of bovine spongiform encephalopathy to humans posed by blood transfusion in
the UK.)

It's one thing to trumpet a theoretical risk. It's another to look at what
the risk actually *is.*

billo


http://www.ncbi.nlm.nih.gov/entrez/q..._uids=14962520

Lancet. 2004 Feb 7;363(9407):417-21.

Comment in:
Lancet. 2004 Feb 7;363(9407):411-2.

Possible transmission of variant Creutzfeldt-Jakob disease by blood
transfusion.

Llewelyn CA, Hewitt PE, Knight RS, Amar K, Cousens S, Mackenzie J, Will
RG.

National Blood Service, Cambridge Centre, Cambridge CB2 2PT, UK.

BACKGROUND: Variant Creutzfeldt-Jakob disease (vCJD) is a novel human
prion disease caused by infection with the agent of bovine spongiform
encephalopathy (BSE). Epidemiological evidence does not suggest that
sporadic CJD is transmitted from person to person via blood transfusion,
but this evidence may not apply to vCJD. We aimed to identify whether
vCJD is transmissible through blood transfusion. METHODS: The national
CJD surveillance unit reported all cases of probable or definite vCJD to
the UK blood services, which searched for donation records at blood
centres and hospitals. Information on named recipients and donors was
provided to the surveillance unit to establish if any matches existed
between recipients or donors and the database of cases of vCJD.
Recipients were also flagged at the UK Office of National Statistics to
establish date and cause of death. FINDINGS: 48 individuals were
identified as having received a labile blood component from a total of
15 donors who later became vCJD cases and appeared on the surveillance
unit's register. One of these recipients was identified as developing
symptoms of vCJD 6.5 years after receiving a transfusion of red cells
donated by an individual 3.5 years before the donor developed symptoms
of vCJD. INTERPRETATION: Our findings raise the possibility that this
infection was transfusion transmitted. Infection in the recipient could
have been due to past dietary exposure to the BSE agent. However, the
age of the patient was well beyond that of most vCJD cases, and the
chance of observing a case of vCJD in a recipient in the absence of
transfusion transmitted infection is about 1 in 15000 to 1 in 30000.

Ermalina 02-06-2004 02:03 AM

Bone/ Blood Meal and Mad Cow Disease
 
Bill Oliver wrote:

In article ,
Janet Baraclough.. wrote:

There is another way to contract nv CJD, via human blood products and
contaminated surgical instruments, which may explain why vegetarians
also develop the disease.

Janet.


Please provide a citation of a case of BSE/vCJD transmitted by blood transfusion.
Blood transfusion is an inefficient method of transmission in sheep, and as
far as I know, there has never been a case in humans. If you have a case,
please cite it.

More important, please cite the actual calculated risk (for example, see:
Dealler S. Transfus Med. 1996 Sep;6(3):217-22 A matter for debate: the risk
of bovine spongiform encephalopathy to humans posed by blood transfusion in
the UK.)

It's one thing to trumpet a theoretical risk. It's another to look at what
the risk actually *is.*

billo



And here's a description of the possible mechanism of infection:

http://www.ncbi.nlm.nih.gov/entrez/q..._uids=15058746

Br J Biomed Sci. 2004;61(1):48-54.

Leucodepletion for transmissible spongiform encephalopathies.

St Romaine C, Hazlehurst G, Jewell AP.

School of Life Sciences, Kingston University, Penrhyn Road,
Kingston-upon-Thames, Surrey KT1 2EE, UK.

Transmissible spongiform encephalopathies (TSEs) have been recognised
around the world for many years. Creutzfeldt-Jakob disease (CJD), one of
the human forms of TSE, has been studied widely and thus far has not
proved a great threat to human health. The emergence of two new
TSEs--bovine spongiform encephalopathy (BSE) in cattle and variant
Creutzfeldt-Jakob disease (vCJD) in humans in the UK--has caused great
concern. BSE has had an economic impact and vCJD is a threat to human
health. It has been shown that these two diseases are caused by the same
prion agent and are linked. Research indicates that vCJD behaves
differently to CJD and there is strong evidence to suggest that vCJD is
present in lymphoid tissues and B lymphocytes, which presents a
theoretical risk that it may be transmitted by transfusion of blood and
blood products. To minimise/prevent this risk, the UK government has
decided that plasma should be sourced from abroad and has instructed the
National Blood Service to leucodeplete all blood and blood products, at
a cost of 70 million pounds per annum, although it is not known if this
will remove this risk.

Ermalina 02-06-2004 02:04 AM

Bone/ Blood Meal and Mad Cow Disease
 
Bill Oliver wrote:

In article ,
Janet Baraclough.. wrote:

Or via blood donations. In the UK, people who recieved a transfusion
during the early 80s are banned from donating blood. Some countries no
longer import any human blood products from the UK.

Janet


Even the FDA has admitted there is no scientific basis for this
decision in the US -- it was purely political, in order to
"reassure" the population.

In fact, this is one example of the BSE hysteria *costing* lives.
The FDA allows fewer and fewer people to donate blood for political
reasons while the demand for blood rises, leading to severe
blood shortages. BSE has cost lives in the US -- because of the
over-reaction to a very small risk.

billo


Please provide a citation for your claim that "Even the FDA has admitted
there is no scientific basis for this decision in the US -- it was
purely political, in order to 'reassure' the population".

paghat 02-06-2004 02:06 AM

Bone/ Blood Meal and Mad Cow Disease
 
User-Agent: NewsWatcher-X 2.2.3b2
Cache-Post-Path:
X-Cache: nntpcache 2.4.0b5 (see http://www.nntpcache.org/)
X-Complaints-To:
Lines: 48
Path: kermit!newsfeed-west.nntpserver.com!newsfeed-east.nntpserver.com!nntpserver.com!diablo.voicenet .com!tdsnet-transit!newspeer.tds.net!sn-xit-02!sn-xit-06!sn-post-01!supernews.com!corp.supernews.com!soggy72.drizzl e.com!user
Xref: kermit rec.gardens:281093

In article , Ermalina
wrote:

Bill Oliver wrote:

In article ,
Janet Baraclough.. wrote:

Or via blood donations. In the UK, people who recieved a transfusion
during the early 80s are banned from donating blood. Some countries no
longer import any human blood products from the UK.

Janet


Even the FDA has admitted there is no scientific basis for this
decision in the US -- it was purely political, in order to
"reassure" the population.

In fact, this is one example of the BSE hysteria *costing* lives.
The FDA allows fewer and fewer people to donate blood for political
reasons while the demand for blood rises, leading to severe
blood shortages. BSE has cost lives in the US -- because of the
over-reaction to a very small risk.

billo


Please provide a citation for your claim that "Even the FDA has admitted
there is no scientific basis for this decision in the US -- it was
purely political, in order to 'reassure' the population".


You can't actually have a rational conversation with Silly Billo, he's a
notorious troll who pokes into issues he knows little about in order to
dissimilate & tell whoppers for the fun of getting anyone who actually
cares about anything upset. He'll try every trolly trick except honesty to
never budge, which over the years has led me to believe he doesn't
personally care about a thing. Bare that in mind if you decide to play
with him. A loony sod can be loads of fun if you're not taken by surprise
how increasingly convoluted & ridiculous he will be whenever anyone
condescends to notice he's back in action, & expect reason to have any
accumulative effect on the unreasonable.

-paghat the ratgirl

--
"Of what are you afraid, my child?" inquired the kindly teacher.
"Oh, sir! The flowers, they are wild," replied the timid creature.
-from Peter Newell's "Wild Flowers"
Visit the Garden of Paghat the Ratgirl:
http://www.paghat.com

Bill Oliver 02-06-2004 03:04 AM

Bone/ Blood Meal and Mad Cow Disease
 
In article ,
Ermalina wrote:
Bill Oliver wrote:



Possible transmission of variant Creutzfeldt-Jakob disease by blood
transfusion.


Note the *possible.*

of vCJD. INTERPRETATION: Our findings raise the possibility that this
infection was transfusion transmitted.


Or not.

Infection in the recipient could
have been due to past dietary exposure to the BSE agent.


Oh.

However, the
age of the patient was well beyond that of most vCJD cases, and the
chance of observing a case of vCJD in a recipient in the absence of
transfusion transmitted infection is about 1 in 15000 to 1 in 30000.


And what was the chance of observing a case of vCJD in a random
transfusion?

That was the question I asked.

I didn't claim that it was impossible. Once again, I am noting that
small risks should be identified as small. As noted in the article you quote,
this is not, in fact, a proven case. But even if it is, the existence
of *one* case after all these years indicates the miniscule risk.

Once again, what *is* the calculated risk? With the presence of
one *possible* case, the hysteria that abounds is hardly appropriate.


billo

Bill Oliver 02-06-2004 04:02 AM

Bone/ Blood Meal and Mad Cow Disease
 
In article ,
Ermalina wrote:
Bill Oliver wrote:

In article ,
Janet Baraclough.. wrote:

Or via blood donations. In the UK, people who recieved a transfusion
during the early 80s are banned from donating blood. Some countries no
longer import any human blood products from the UK.

Janet


Even the FDA has admitted there is no scientific basis for this
decision in the US -- it was purely political, in order to
"reassure" the population.

In fact, this is one example of the BSE hysteria *costing* lives.
The FDA allows fewer and fewer people to donate blood for political
reasons while the demand for blood rises, leading to severe
blood shortages. BSE has cost lives in the US -- because of the
over-reaction to a very small risk.

billo


Please provide a citation for your claim that "Even the FDA has admitted
there is no scientific basis for this decision in the US -- it was
purely political, in order to 'reassure' the population".


The fact that this is a "theoretical" risk is openly noted by the
FDA -- if you look at its labeling guidance the FDA demands the
following warning (see:

http://www.aabb.org/members_only/arc...dcoi101001.htm

)

WARNING: Because whole blood and blood components are made from human blood,
they may carry a risk of transmitting infectious agents, eg viruses, and theoretically
the Creutzfeldt-Jakob disease (CJD) agent.?


Note that "theoretically." In other words, they don't know what the
risk actually is.

In fact, here's the FDA position as described by the AABB:

(see
http://www.aabb.org/members_only/arc...ins/ab99-8.htm
)

So far, there is no evidence that anyone who has traveled to the UK has
become infected with nvCJD. The AABB does not believe that people who
have traveled there should be concerned about their health. To date,
there is also no evidence that nvCJD can be transmitted by blood
transfusions, or by any type of person-to-person contact. However,
until more research is done and conclusive evidence can be found
regarding how nvCJD is transmitted, the FDA is requiring this
precautionary donor deferral to safeguard against the unproven
possibility that nvCJD could be spread by blood transfusion.

***** end excerpt ****

Ah yes, a precaution to safeguard against the unproven possibility.

That's rock solid science, yessirree.


As noted by the American Red Cross in

http://my.webmd.com/content/article/...177_2417_00_07

************************************
begin excerpt

In 2001, in an attempt to protect the nation's blood supply from mad
cow disease, the FDA banned blood donation from people who had
previously lived in Europe. But blood industry representatives are
appealing to the agency to lift the ban, saying that it exacts a
tremendous toll on our blood supply.

Currently, donations are banned from:

* Anyone who has lived in the U.K. for three months or longer since 1980
* Anyone who has lived anywhere in Europe for six months since 1980
* Anyone who has received a blood transfusion in the U.K.

Mad cow disease is a degenerative brain disease in animals. Infected
animals act crazy, or "mad," displaying changes in mood such as
nervousness or agitation and having difficulty standing up, and usually
die within two weeks to six months. Mad cow disease seems to spread to
people through eating infected beef. Some animal studies suggest that
it may be possible to transmit the disease through blood transfusion,
prompting concerns among blood bank and FDA officials about
safeguarding the blood supply.

Scientists still don't know a lot about mad cow disease and how it is
transmitted, nor do doctors have a test to screen for it.

In humans, mad cow disease is called new variant Creutzfeldt-Jakob
disease, or vCJD. Most of the 140 vCJD cases identified so far have
occurred in the U.K. The first U.S. case occurred in October 2002, but
it is believed the patient contracted it while in the U.K.

Still, there is no evidence to suggest that the disease has spread
through blood or blood products. "(But) the concern is that the
incubation period can be quite long. Even if the risk is quite small,
you might not see it in a hundred or so cases. After the experience in
the '80s (with HIV transmission through the blood supply), the public
expects us to do too much too soon rather than too little too late,"
said Peter L. Page, MD, senior medical officer at the American Red
Cross.
***** end excerpt *****

Yes, Virginia, political. That's what "the public expects us
to do too much too soon" means.


The AABB notes the effect this policy of "too much too soon" has
on the blood supply. See

http://www.aabb.org/pressroom/press_...rtse062701.htm

begin excerpt

*********

The AABB acknowledges the FDA's need to reach a compromise on whether
to implement any new donor deferral policies while at the same time
carefully balancing patient welfare against all relevant risks and
benefits to patient health.

Currently, an individual will be deferred or disqualified as a blood
donor if he or she has lived in the United Kingdom for a cumulative
period of six months or more from 1980-1996. This policy was
established by the FDA in order to prevent a possible but not confirmed
risk of transmitting vCJD through blood transfusion.

However, stricter criteria currently are being debated, which could
adversely affect the availability of blood. Although it is difficult to
measure precisely the effect of a stricter deferral, best estimates
suggest that anywhere between five and ten percent of potential blood
donors could be eliminated.

"We recognize that a theoretical risk of transmission of TSE through
blood transfusion exists," said Klein. "At the same time, availability
of blood is also a safety issue and we must balance this risk against
the potential risk of TSE transmission through blood."

********
end excerpt


Here's what are to tell people who are deferred:

IF YOU WERE DEFERRED AS A BLOOD DONOR BECAUSE OF TRAVEL TO THE UNITED KINGDOM?

* The deferral is a result of a Food and Drug Administration (FDA)
recommendation that anyone who spent more than six months in the
United Kingdom (UK) between 1980 and 1996 be deferred from donating
blood. We would like to reassure you, however, that you should not
be alarmed about your health, and we do not believe that it is
necessary for you to see your doctor as a result of this deferral.

* The FDA is taking a very conservative approach to make sure that
an unusual and rare brain disease called "new variant
Creutzfeldt-Jakob disease" (nvCJD) does not affect the US blood
supply. In fact, this travel deferral is an addition to other CJD
deferrals that have been in place for many years.

* New variant CJD is extremely rare, and has infected only a very
small number of people, mostly from England or other parts of the UK (England,
Scotland, Wales, Northern Ireland, Channel Islands and Isle of
Mann). It is likely, but not yet proven, that there is a connection
between eating beef from cattle infected with a similar disease.

* There is no evidence that travelers to the UK, even those who may
have eaten beef while traveling there, have become infected with
nvCJD. Scientists do not believe that nvCJD can be transmitted
through casual or even intimate (sexual) contact with an infected
person. To date, there is no evidence that nvCJD can be spread
person-to-person by blood transfusions. However, until more
research is done and conclusive evidence can be found regarding how
nvCJD is transmitted, the FDA is requiring this precaution.

* Your deferral period is (institution's deferral period here). We share
your disappointment, but please know that as new information about
nvCJD, or even a blood test, becomes available, it may be possible
someday to reinstate you as a donor.

* Thank you for your generous spirit. Your desire to save lives by
donating blood makes all the difference for patients in need, and
we are grateful to you.

(http://www.aabb.org/members_only/arc...ins/ab99-8.htm)

So, it is a theoretical risk in which there is no actual evidence that
travellers to the UK are at risk and they are doing it to be extremely
cautious and do "too much too soon." And in doing so, they are decreasing
the blood supply by 10 - 15% at a time with blood demand is increasing.

As noted by Celso Bianco, MD in his review for Hematology:

(see http://www.aabb.org/members_only/arc...ins/ab96-4.htm )

The theoretical possibility of CJD transmission by transfusion has been
examined by other investigators. A study of transfusion histories of
202 definite and probable cases of CJD which had been part of
prospective studies performed in England and Wales between 1980-84 and
1990-92, showed that 21 of the patients had received blood transfusions
and 29 had donated blood (8). The frequency of blood transfusions or
donations did not differ between CJD cases and matched controls,
leading the investigators to conclude that the evidence did not suggest
that transfusion was a major risk factor for development of CJD (8). No
cases of CJD among hemophiliacs have been reported in the medical
literature. The Medline database contains 1,485 references on CJD and
6,385 references on hemophilia between January 1976 and October 1994.
None of these references links CJD and hemophilia. An extensive review
of mortality data performed by L. Schonberger from the CDC did not
identify a single CJD death in individuals with a clott

On December 15, 1994, the issue of CJD and transfusion was reviewed by
the FDA Blood Products Advisory Committee. After extensive discussion,
the Committee recommended that in-date cellular products of blood from
donors who later develop CJD should be withdrawn from distribution. In
case these products were transfused, the Committee recommended that
physicians and recipients be notified. In the case of plasma pooled for
further manufacture, the Committee recommended against recall of
manufactured products, because of the lack of evidence for
transmission. The hemophilia community appeared to be quite
dissatisfied with this recommendation, leading the FDA to convene a new
Advisory Committee to review the possibility of transmission of CJD by
plasma derivatives. The Special Advisory Committee met on June 22,
1995, and recommended that all plasma products containing plasma from
individuals who later died of CJD, including albumin, should be
withdrawn from the market, despite the lack of evidence for transmissib

Lookback studies have been organized around blood donors who later
developed CJD. These studies involve identification of recipients and
review of their health status. So far, review of the cause of death of
35 recipients of these units indicated that none had developed CJD or
other central nervous system disease. Once case of potential
transmission to a liver transplant recipient who also received
transfusions of albumin has recently been reported. One of the albumin
donors died three years later from a dementia clinically characterized
as CJD (9). Obviously, the liver transplant recipient was exposed to a
variety of drugs and biologics, making it difficult to determine the
exact source of disease. Unfortunately, because of the very low
incidence of CJD and the long incubation period, there will be a long
period of time before more definitive answers become available. In the
interim, CJD is being approached as a disease which can theoretically
be transmitted by blood and blood products.

***** end excerpt ****


The risk is small. Period.






billo

Ermalina 02-06-2004 06:02 AM

Bone/ Blood Meal and Mad Cow Disease
 
Bill Oliver wrote:

More important, please cite the actual calculated risk (for example, see:
Dealler S. Transfus Med. 1996 Sep;6(3):217-22 A matter for debate: the risk
of bovine spongiform encephalopathy to humans posed by blood transfusion in
the UK.)

It's one thing to trumpet a theoretical risk. It's another to look at what
the risk actually *is.*

billo


Regarding the risk of transmission of BSE/vCJD by blood transfusion in
the U.S.:

1. What doofus would rely on a 1996 paper for an assessment of risk of
transmission? The link between BSE and vCJD was not recognized until
1996. Even now, our "ignorance is encyclopedic."

2. In the words of the National Acadamies of Science report entitled
"Advancing Prion Science (published in 2004)":

"These studies provide some assurances for the lack of blood
transmission of TSE agents, but the inherent deficiencies of
epidemiological approaches, the rarity of the conditions, the difficulty
of correctly diagnosing true cases, and the long incubation period prior
to case expression make these assurances both tentative and infirm. This
is particularly true for assessing the risk of transmitting the vCJD
agent through the transfusion of blood or one of its derivatives since
this is such a new TSE."

3. Consequently, Mr. Oliver, you ask a question that only a FOOL would
consider answerable at this time.

So, what's your answer? ;-)

Bill Oliver 03-06-2004 03:02 AM

Bone/ Blood Meal and Mad Cow Disease
 
In article ,
Ermalina wrote:
Bill Oliver wrote:


1. What doofus ...


Ah, yes, the standard approach of someone who doesn't have
the facts, start with the personal attacks.

In fact, a 1996 estimate is a good place to start, since
the risk has gone down since then. Thus, a 1996 estimate
places an *upper bound* on the actual risk. You do understand
the concept of upper bound?


2. In the words of the National Acadamies of Science report entitled
"Advancing Prion Science (published in 2004)":

"These studies provide some assurances for the lack of blood
transmission of TSE agents, but the inherent deficiencies of
epidemiological approaches, the rarity of the conditions, the difficulty
of correctly diagnosing true cases, and the long incubation period prior
to case expression make these assurances both tentative and infirm. This
is particularly true for assessing the risk of transmitting the vCJD
agent through the transfusion of blood or one of its derivatives since
this is such a new TSE."



Which makes my point. The event is so *rare* that it is difficult
to get decent statistics. It's like calculating the probability
of being hit by a meteorite.

But, hey. don't let that stop you from engaging in hysteria and
in pretending that every little exposure to things like bone
meal will end in death. And don't let that stop you from decreasing
the blood supply by 10-15% -- which results in *real* death,
and *real* disease, and *real* costs. But *those* deaths, and
*those* illnesses and *those* costs are a small price to pay
for a theoretical risk that is so miniscule that the *rarity*
of it makes calculating the risk difficult.

What was that you were saying about a "doofus?" What kind
of doofus would choose to have people die because they can't
get the right kind of blood in an emergency in order to
placate an irrational hysteria?


3. Consequently, Mr. Oliver, you ask a question that only a FOOL would
consider answerable at this time.

So, what's your answer? ;-)



Well, I'll go with FOOLS like Dr. Bernadette Healy -- who calls the
risk "tiny." ( http://news.bbc.co.uk/1/hi/health/1503744.stm)

Or FOOLS like Brown, et al. in The distribution of infectivity
in blood components and plasma derivatives in experimental models
of transmissible spongiform encephalopathy. Transfusion
38(9):810,1998 who call it "minimal."

Or FOOLS like Wilson K, Code C, Ricketts MN., Risk of acquiring
Creutzfeldt-Jakob disease from blood transfusions: systematic
review of case-control studies. BMJ. 2000 Jul 1;321(7252):17-9.
who conclude: "Case-control studies do not suggest a risk of
developing Creutzfeldt-Jakob disease from blood transfusion. Rather,
a trend seems to exist towards a lower frequency of previous
blood transfusion in patients with Creutzfeldt-Jakob disease
than in controls."

Or FOOLS like Ricketts MN, Brown P. Transmissible spongiform encephalopathy
update and implications for blood safety. Clin Lab Med. 2003 Mar;23(1):129-37
who conclude "At this time, the accumulated evidence does not support the
implementation of measures targeted against the risk of transfusion
transmission of sporadic, familial, or iatrogenic CJD."


Or FOOLS like Brown P. Variant CJD transmission through blood: risks to
predictors and "predictees". Transfusion. 2003 Apr;43(4):425-7. who
noted: "With the passage of time, systematically collected
epidemiologic data substantiated the absence of CJD transmissions in
blood recipients and began to weigh more heavily on the perception of
risk to humans. It was finally decided that any such risk was
negligible, and plasma pools were no longer discarded upon knowledge of
a contributing CJD donor (although deferrals designed to eliminate
"high-risk" donor categories, such as growth hormone and dura mater
recipients, remained in force).. .



1) While it is true that the number of vCJD "carriers" remains unknown,
early estimates of as many as 100,000 cases have in recent years
shriveled to a maximum of just a few hundred cases, assuming the
entirely reasonable estimate of 15 to 20 years as the average
incubation period. 1,2 The increasing time period during which the
evolution of cases has been observed continues to improve the precision
of mathematical modeling and to alleviate concern about the extent of
infection of the exposed UK population. 2.

2) Although the concentration of prion protein is indisputably higher
in the organs of patients with vCJD than sporadic CJD, and probably
does indicate a correspondingly higher concentration of infectivity,
infectivity is demonstrable in tissues of patients with both diseases,
3,4 and no studies directly comparing infectivity levels have been
performed. Furthermore, the presence of infectivity in
blood-interactive organs is not equivalent to infectivity in the blood,
as is well demonstrated in studies of circulating and splenic
lymphocytes in an experimental mouse model of scrapie. 5 3.

3) Transmission of disease in experimental models via blood and blood
components should not be considered in isolation. The only meaningful
approach comes from a consideration of data that compare infectivity in
vCJD and BSE experimental models to other experimental disease models
or that compare epidemiologic observations in humans. These data are
summarized in Table 1 (references 6-9 and unpublished data) and lead to
the conclusion that, at the very least, the risk associated with vCJD
and BSE is not yet demonstrably worse than the risk from non-vCJD forms
of disease, which has been shown to be negligible.

end excerpt.


Considering the millions and millions of blood transfusions that
have occurred since the BSE hysteria over a decade ago, and in that
time there has only been *one* ***possible*** example, which is
actually *more* likely to be diet-related, I'll go along with
the FOOLS who use words like "tiny," "negligible," and "minimal."

I would rate it somewhere less than a thousand times less than
being hit by lightning and *perhaps* slightly more than being
hit by a meteor as I go out to get my mail tomorrow morning.

But hey, all these people are FOOLS, I know, and are slaves
to the evil medical-industrial complex. Go with the experts
like paghat. Watch out, the sky is falling.

And that's Dr. Oliver, to you.

billo

Tom Jaszewski 03-06-2004 03:06 AM

Bone/ Blood Meal and Mad Cow Disease
 
Nice to see you still minimizing behind the guise of science....


On Tues, 01 Juno 2004 23:16:01 -0000, (Bill Oliver)
wrote:

The BSE hysteria is a wonderful example of hysteria overtaking
science.


bilbo baggins


Acts of creation are ordinarily reserved for gods and poets. To plant a pine, one need only own a shovel.
-- Aldo Leopold

Tom Jaszewski 03-06-2004 03:08 AM

Bone/ Blood Meal and Mad Cow Disease
 
Like billbo is a shill?



On Tue, 01 Jun 2004 23:56:05 -0000, (Bill Oliver)
wrote:

look at what
the risk actually *is.*

billo


Acts of creation are ordinarily reserved for gods and poets. To plant a pine, one need only own a shovel.
-- Aldo Leopold

Tom Jaszewski 03-06-2004 03:09 AM

Bone/ Blood Meal and Mad Cow Disease
 
oh billbo please stick to gardening, oops then we get Monsanto shill
diatribes......


On Thu, 03 Jun 2004 01:20:37 -0000, (Bill Oliver)
wrote:

You do understand
the concept of upper bound?


Acts of creation are ordinarily reserved for gods and poets. To plant a pine, one need only own a shovel.
-- Aldo Leopold

Will 03-06-2004 06:02 AM

Bone/ Blood Meal and Mad Cow Disease
 
On Thu, 03 Jun 2004 01:20:37 -0000, I found this from
(Bill Oliver) :

And that's Dr. Oliver, to you.


Who did you say you wrked for?

Janet Baraclough.. 03-06-2004 01:02 PM

Bone/ Blood Meal and Mad Cow Disease
 
The message
from (Bill Oliver) contains these words:


In fact, a 1996 estimate is a good place to start, since
the risk has gone down since then.


The risk of eating BSE-infected beef in Britain, has gone down since
then. That is not the same as saying, that the incidence of nv CJD
infection will decrease, because a) virtually all the meat-eating
population of the UK was exposed to BSE for at least a decade and B) we
still don't know the incubation period, or what other factors activate a
dormant infection.

2. In the words of the National Acadamies of Science report entitled
"Advancing Prion Science (published in 2004)":

"These studies provide some assurances for the lack of blood
transmission of TSE agents, but the inherent deficiencies of
epidemiological approaches, the rarity of the conditions, the difficulty
of correctly diagnosing true cases, and the long incubation period prior
to case expression make these assurances both tentative and infirm. This
is particularly true for assessing the risk of transmitting the vCJD
agent through the transfusion of blood or one of its derivatives since
this is such a new TSE."



Which makes my point. The event is so *rare* that it is difficult
to get decent statistics.


You've misinterpreted the above statement and got it back to front.

It says that because of the lack of statistics, any assurances about
lack of blood-transmission are tentative and infirm.

Or FOOLS like Wilson K, Code C, Ricketts MN., Risk of acquiring
Creutzfeldt-Jakob disease from blood transfusions: systematic
review of case-control studies. BMJ. 2000 Jul 1;321(7252):17-9.
who conclude: "Case-control studies do not suggest a risk of
developing Creutzfeldt-Jakob disease from blood transfusion.


That 2000 research has been overtaken by events in the UK. Of the
140-odd UK cases of nv CJD, 15 were blood donors. The recipients of
their donations are monitored, and since 2000, one of those recipients
has developed nv CJD.

Or FOOLS like Ricketts MN, Brown P. Transmissible spongiform encephalopathy
update and implications for blood safety. Clin Lab Med. 2003
Mar;23(1):129-37
who conclude "At this time, the accumulated evidence does not support the
implementation of measures targeted against the risk of transfusion
transmission of sporadic, familial, or iatrogenic CJD."


Those forms of CJD are not related to BSE. The concern is about the new
variant of CJD.

\/\/\/\/\/\

Or FOOLS like Brown P. Variant CJD transmission through blood: risks to
predictors and "predictees". Transfusion. 2003 Apr;43(4):425-7. who
noted: "With the passage of time, systematically collected
epidemiologic data substantiated the absence of CJD transmissions in
blood recipients


Out of date, see above.

Furthermore, the presence of infectivity in
blood-interactive organs is not equivalent to infectivity in the blood,


However, it does pose the problem of human cross-contamination by
surgical instruments, since the prions are not susceptible to
sterilisation techniques.


Considering the millions and millions of blood transfusions that
have occurred since the BSE hysteria over a decade ago, and in that
time there has only been *one* ***possible*** example, which is
actually *more* likely to be diet-related, I'll go along with
the FOOLS who use words like "tiny," "negligible," and "minimal."


You're conflating statistics. There are only 15 *known* nv-CJD
infected human blood donors; their blood never reached "millions and
millions" of recipients. One case of infection from only 15 donors is
rather more worrying.

The "decade ago", is not yet grounds for complacency either, since we
still don't know the full range of the incubation period. Recent
research on discarded appendixes and tonsils showed that some of the UK
population are still carrying the prions.

Janet.


Bill Oliver 04-06-2004 03:02 PM

Bone/ Blood Meal and Mad Cow Disease
 
In article ,
Janet Baraclough.. wrote:
The message
from (Bill Oliver) contains these words:


In fact, a 1996 estimate is a good place to start, since
the risk has gone down since then.


The risk of eating BSE-infected beef in Britain, has gone down since
then. That is not the same as saying, that the incidence of nv CJD
infection will decrease, because a) virtually all the meat-eating
population of the UK was exposed to BSE for at least a decade and B) we
still don't know the incubation period, or what other factors activate a
dormant infection.


But you do know the prevalance of symptomatic disease, and that
is decreasing. You also know a good deal about conventional
CJD and you know that the route of transmission and pertinent
vectors are essentially the same. In order for the hysterical
view to be correct, you would not only have to posit not
only that "we still don't know the incubation period" but
*also* that this unknown incubation period is actively
*increasing* in order to explain the decrease in the
symptomatic cohort. Otherwise, a constant percentage
of infected people would become symptomatic. Since
fewer people are becoming symptomatic, either the
number of infections is decreasing or the incubation
period is magically increasing.

You know that the exposure is decreasing, the prevalence
of symptomatic disease is decreasing, you know that there
is no evidence of significant other methods of transmission,
and you have no rational reason to believe that the decrease
in symptomatic patients is because there is a large reservoir
of disease that is busily increasing its dormancy period simply
to stay hidden.

Unless you believe in magic the risk is decreasing, and the
1996 calculations provide an upper bound.



You're conflating statistics. There are only 15 *known* nv-CJD
infected human blood donors; their blood never reached "millions and
millions" of recipients. One case of infection from only 15 donors is
rather more worrying.


Well, no. I entered this because a respondent used the ban
on donors as evidence of risk. It is not. And the millions
and millions of recipients apply to that. Further, your
claim provides its own problem. There were only 15 known
vCJD donors in this study. Are you now positing that
there are not many, many untested prion-positive donors?
In fact, and if you really want, I can provide you with
articles that provide good evidence that *lots* of
people with prions have given blood. Where are *those*
cases of vCJD?


The "decade ago", is not yet grounds for complacency either, since we
still don't know the full range of the incubation period. Recent
research on discarded appendixes and tonsils showed that some of the UK
population are still carrying the prions.


Right. And you posit that this incubation period is *increasing* because
those clever prions just don't want to get caught. That's why
the number of patients with disease is decreasing, right?

billo



All times are GMT +1. The time now is 11:49 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
GardenBanter