- Hello, Jeff - I believe that we are now seeing all forms
of prion disease mutating. Attached below is a Scrapie-LIKE disease update.
Atypical Scrapie, Atypical BSE in cattle and now, an atypical BSE in sheep
indicates that this is not the abnormal, but, the beginning of the norm.
Until, we find out what causes the prion to misfold and figure out the
"trigger" we will cotninue to be perplexed by this disease.
-
- Although, scrapie was first identified in the 1700s,
TSE and all of the prion diseases are really quite new. Prion disease
is unlike viral disease. Antigenic drift and shifts in viral diseases,
such as occur with Influenza can almost be predictable. Mechanisms of
prion folding and misfolding are, truly, alien to us. We now have a new
trend in prion disease or TSEs and we don't know how and why or how to
stop it.
-
- There is a good possibility that atypical mutations of
all prion diseases has basis in an eroding genetic evolution of the victims
of the disease. We may be polluting ourselves into oblivion.
-
- Patricia
-
- Mysterious BSE-Like Disease Found In Sheep
-
- From ProMED-mail 4-9-4
-
- By Debora MacKenzie] NewScientist.com news service 8
Apr 2004
-
- A massive research programme to find out whether BSE
is circulating in British sheep has turned up its first suspicious result.
But while scientists say the sheep did not have conventional BSE, they
cannot rule out the possibility that it could have had a new form of BSE
(mad cow disease) that has adapted to sheep.
-
- Britain's Department for Environment, Food and Rural
Affairs [DEFRA] has announced that the Veterinary Laboratories Agency (VLA)
in Weybridge, England, had found "a type of scrapie not previously
seen in the UK". Scrapie is a sheep disease similar to BSE which is
not generally thought to harm people.
-
- The Department for the Environment, Food and Rural Affairs
(DEFRA) said the disease-causing prion detected in the sheep's brain "had
some characteristics similar to experimental BSE in sheep", but that
on other tests it resembled neither BSE nor "previously recognised
types of scrapie". The UK's Food Standards Agency said in a statement:
"Uncertainties still remain on this issue. However, based on the best
scientific evidence to date, we are not advising against eating lamb and
sheep meat."
-
- There have long been fears that sheep which ate cattle-derived
meat and bone meal during Britain's BSE epidemic in the 1980s might have
acquired BSE, although they have never been confirmed. Unlike BSE in cattle,
prion diseases spread directly from sheep to sheep. So any BSE in sheep
could still be circulating despite subsequent bans on animal-derived feed.
Furthermore, sheep experimentally fed BSE develop a disease indistinguishable
from ordinary scrapie, making detection very difficult. Yet the prion from
such animals still behaves like BSE, and could cause the fatal human disease
vCJD. Worse, sheep carry prions in more tissues than cattle, including
the muscle that people eat, so BSE-infected sheep could cause more human
disease than mad cows.
-
- A previous attempt to determine whether British sheep
had acquired BSE went spectacularly wrong in 2001 when sheep and cattle
brains were mixed up in the lab. But since then, the VLA has tested the
brains of all 1019 newly reported cases of scrapie, as well as 1125 scrapie
brains dating back to 1998, with tests designed to distinguish scrapie
from BSE.
-
- The new result announced on Wednesday, from a sheep recently
reported with scrapie symptoms, is the first to give results that resembled
BSE. Danny Matthews of the VLA told New Scientist that in a prion test
called a western blot, the sheep's brain did not bind an antibody called
P4. P4 also does not bind prions from sheep experimentally infected with
BSE, but does bind all but one forms of scrapie tested with it.
-
- Also like BSE, the form of the prion without a sugar
attached to it had a lower molecular weight than the form found in scrapie.
But the ratio of prions with different numbers of sugars on them looked
like scrapie, not BSE, says Matthews. Most conclusively, immunohistochemistry
(IHC), in which thin slices of the sheep's brain were stained with various
antibodies, showed prions had accumulated in different parts of the brain
and different kinds of cells from BSE -- or any known form of scrapie.
-
- The IHC pattern reliably indicates BSE, says Matthews,
having been constant in the 100 experimentally infected sheep of different
genetic varieties tested so far. But so little scrapie has been tested,
he says, it is not known if one strain might give these results on the
tests. One possibility, he says, is that the sheep might have been carrying
a prion initially derived from BSE. Passage into new species is well known
to change prions.
-
- BSE from experimentally infected sheep has so far been
passed to just one more round of sheep, with no apparent change. "But
we don't know if passage through many sheep, of different genetic types,
might change it so it no longer gives the same pattern in IHC or western
blots," says Matthews. "Those experiments are underway now."
-
- Any such new incarnation of BSE in sheep may -- or may
not -- have lost its ability to harm humans.
-
- http://www.newscientist.com/news/news.jsp?id=ns99994869
-
- -- ProMED-mail <promed@promedmail.org>
-
- [As rightly commented, the main current worry, related
to a possible presence of BSE in sheep, is its infection routes. Cattle
are thought to be infected with BSE mainly, if not only, orally -- namely
by the consumption of infected meat & bone meals (MBMs). The banning
of this commodity is regarded to terminate the infection cycle.
-
- Scrapie spreads among sheep laterally (from one animal
to another via direct or indirect contact) and maternally (from a dam to
its offspring, either vertically or laterally by close post-parturient
association). Thus -- provided BSE, if infecting sheep, behaves like the
scrapie agent -- the discontinuation of feeding sheep with MBMs will not
terminate the infection cycle. - Mod.AS]
-
-
-
- Date: Fri, 9 Apr 2004 From: ProMED-mail <promed@promedmail.org>
Source: NewScientist.com news service, 8 Apr 2004 [edited] <http://www.newscientist.com/news/news.jsp?id=ns99994869>
-
-
- Mysterious BSE-like disease found in sheep
- ------------------------------------------
- A massive research programme to find out whether BSE
is circulating in British sheep has turned up its first suspicious result.
But while scientists say the sheep did not have conventional BSE, they
cannot rule out the possibility that it could have had a new form of BSE
(mad cow disease) that has adapted to sheep.
-
- Britain's Department for Environment, Food and Rural
Affairs [DEFRA] has announced that the Veterinary Laboratories Agency (VLA)
in Weybridge, England, had found "a type of scrapie not previously
seen in the UK". Scrapie is a sheep disease similar to BSE which is
not generally thought to harm people.
-
- The Department for the Environment, Food and Rural Affairs
(DEFRA) said the disease-causing prion detected in the sheep's brain "had
some characteristics similar to experimental BSE in sheep", but that
on other tests it resembled neither BSE nor "previously recognised
types of scrapie". The UK's Food Standards Agency said in a statement:
"Uncertainties still remain on this issue. However, based on the best
scientific evidence to date, we are not advising against eating lamb and
sheep meat."
-
- There have long been fears that sheep which ate cattle-derived
meat and bone meal during Britain's BSE epidemic in the 1980s might have
acquired BSE, although they have never been confirmed. Unlike BSE in cattle,
prion diseases spread directly from sheep to sheep. So any BSE in sheep
could still be circulating despite subsequent bans on animal-derived feed.
Furthermore, sheep experimentally fed BSE develop a disease indistinguishable
from ordinary scrapie, making detection very difficult. Yet the prion from
such animals still behaves like BSE, and could cause the fatal human disease
vCJD. Worse, sheep carry prions in more tissues than cattle, including
the muscle that people eat, so BSE-infected sheep could cause more human
disease than mad cows.
-
- A previous attempt to determine whether British sheep
had acquired BSE went spectacularly wrong in 2001 when sheep and cattle
brains were mixed up in the lab. But since then, the VLA has tested the
brains of all 1019 newly reported cases of scrapie, as well as 1125 scrapie
brains dating back to 1998, with tests designed to distinguish scrapie
from BSE.
-
- The new result announced on Wednesday, from a sheep recently
reported with scrapie symptoms, is the first to give results that resembled
BSE. Danny Matthews of the VLA told New Scientist that in a prion test
called a western blot, the sheep's brain did not bind an antibody called
P4. P4 also does not bind prions from sheep experimentally infected with
BSE, but does bind all but one forms of scrapie tested with it.
-
- Also like BSE, the form of the prion without a sugar
attached to it had a lower molecular weight than the form found in scrapie.
But the ratio of prions with different numbers of sugars on them looked
like scrapie, not BSE, says Matthews. Most conclusively, immunohistochemistry
(IHC), in which thin slices of the sheep's brain were stained with various
antibodies, showed prions had accumulated in different parts of the brain
and different kinds of cells from BSE -- or any known form of scrapie.
-
- The IHC pattern reliably indicates BSE, says Matthews,
having been constant in the 100 experimentally infected sheep of different
genetic varieties tested so far. But so little scrapie has been tested,
he says, it is not known if one strain might give these results on the
tests. One possibility, he says, is that the sheep might have been carrying
a prion initially derived from BSE. Passage into new species is well known
to change prions.
-
- BSE from experimentally infected sheep has so far been
passed to just one more round of sheep, with no apparent change. "But
we don't know if passage through many sheep, of different genetic types,
might change it so it no longer gives the same pattern in IHC or western
blots," says Matthews. "Those experiments are underway now."
-
- Any such new incarnation of BSE in sheep may -- or may
not -- have lost its ability to harm humans.
-
- [byline: Debora MacKenzie]
-
- -- ProMED-mail <promed@promedmail.org>
-
- [As rightly commented, the main current worry, related
to a possible presence of BSE in sheep, is its infection routes. Cattle
are thought to be infected with BSE mainly, if not only, orally -- namely
by the consumption of infected meat & bone meals (MBMs). The banning
of this commodity is regarded to terminate the infection cycle.
-
- Scrapie spreads among sheep laterally (from one animal
to another via direct or indirect contact) and maternally (from a dam to
its offspring, either vertically or laterally by close post-parturient
association). Thus -- provided BSE, if infecting sheep, behaves like the
scrapie agent -- the discontinuation of feeding sheep with MBMs will not
terminate the infection cycle. - Mod.AS]
-
-
-
- [1] Date: Wed 7 Apr 2004 From: Mary Marshall <tropical.forestry@btinternet.com>
Source: FarmersWeekly Interactive (FWI), 7 Apr 2004 [edited] <http://www.fwi.co.uk/article.asp?con=14329&sec=18&hier=2>
-
-
- Unusual scrapie type found
- --------------------------
- The Veterinary Laboratories Agency has informed the Department
for Environment Food and Rural Affairs (DEFRA), the Devolved Administrations,
and the Food Standards Agency, of a type of scrapie not previously seen
in the UK. The VLA and other European laboratories with expertise in scrapie-like
diseases have analyzed tissue samples from the sheep.
-
- A meeting of the scientific experts who performed these
tests concluded that this case could not be considered to be BSE in sheep,
although it does not behave like known types of scrapie either. Further
investigation will be needed before more can be said about how this unusual
result should be described, according to DEFRA.
-
- The Voluntary Scrapie Flocks Scheme, part of the National
Scrapie Plan, provides free scrapie genotype testing of all sheep on the
eligible farm. Scrapie susceptible animals -- NSP type 2, 3, 4 and 5 rams
and type 4 and 5 females -- identified on these farms will be culled and
replaced with stock that is more resistant.
-
- ****** [2] Date: Wed 7 Apr 2004 From: ProMED-mail <promed@promedmail.org>
Source: DEFRA news release 139/04, 7 Apr 2004 [edited] <http://www.defra.gov.uk/news/2004/040407b.htm>
-
-
- DEFRA investigates an unusual scrapie case
- ------------------------------------------
- The VLA and other European laboratories with expertise
in scrapie-like diseases have now applied several rapid diagnostic methods
to tissue samples from a sheep with suspected scrapie. Some of the methods
have indicated that the case does not appear to resemble previously recognized
cases of scrapie and, although there were differences, it had some characteristics
similar to experimental BSE in sheep and also to an experimental strain
of sheep scrapie. More importantly, though, microscopic analysis of brain
material showed that the case neither resembled previously recognized types
of scrapie or experimental BSE in sheep.
-
- A meeting of the scientific experts who performed these
analyses, held on 30 Mar 2004, concluded that this case could not be considered
to be BSE in sheep, although it does not behave like known types of scrapie
either. Further investigation will be needed before more can be said about
how this unusual result should be described.
-
- DEFRA's chief scientific adviser, Professor Howard Dalton,
said "The UK, and especially the VLA, have played an important part
in improving the diagnostic methods available for identifying TSEs in sheep.
As we continue to assess more samples with these improved methods, it is
likely that we will continue to find samples, such as this, which fall
outside our current knowledge of the disease. DEFRA, as it does with all
research, will continue to consult scientific experts to ensure that we
are investigating these cases using the best available techniques and methods."
-
- The National Scrapie Plan remains unaffected by this
new result and SEAC [Spongiform Encephalopathy Advisory Committee] will
be consulted in the near future.
-
- Notes for editors: 1. Scrapie is a fatal neurological
sheep disease belonging to a group of diseases called transmissible spongiform
encephalopathies (TSEs), including BSE in cattle and CJD in humans. It
has been present in the national flock for over 250 years. It is not considered
to be transmissible to humans. 2. There is a theoretical risk that BSE
could be present in sheep, masked by scrapie, but it has not been found
naturally occurring in sheep. 3. There is as yet no definitive diagnostic
method that can rapidly distinguish different TSEs, for example, scrapie
from BSE. Consequently, from time to time the scrapie surveillance programs
in EU member states throw up unusual results that merit further investigations
(DEFRA press release 371/03 refers <http://www.defra.gov.uk/news/2004/../2003/030911a.htm>.
4. The VLA have applied several different methods to the sample to compare
it to a wide range of previously detected scrapie cases, experimental BSE
in sheep, and an experimental strain of scrapie, termed CH1461. 2 main
methods have been used in this analysis: a. Western blot (WB) This involves
taking a sample of the brain and treating it with an enzyme -- proteinase
k -- to destroy the normal prion protein (PrPC). The diseased form of the
protein (PrPSc) is able to withstand this treatment and is then separated
from other cellular material on a gel. A blot is taken of the gel and the
PrPSc is visualized using specific antibodies. b. Immunohistochemistry
(IHC) This involves taking thin slices of the brain, and by using special
(antibody) markers to detect the PrPSc it is possible to see disease specific
patterns of PrPSc distribution in the brain under a microscope. The Western
blot method found that the sample did not appear to resemble previously
recognized cases of scrapie and, although there were some differences,
some characteristics were similar to experimental BSE in sheep and also
the experimental strain of sheep scrapie, CH1461. IHC found that it neither
resembled previously recognized types of scrapie or experimental BSE in
sheep 5. The tissue sample has now been analyzed using a total of 5 different
diagnostic methods claiming to be able to differentiate between scrapie
and experimental BSE in sheep. 2 were performed at the VLA and 3 were performed
in other European laboratories. 6. The VLA is the European Reference Laboratory
for TSEs and is responsible for coordinating such investigations into unusual
cases. Their findings will be considered by the European Food Safety Authority's
committee of TSE experts and in the UK by the SEAC. 7. The genotype of
the suspect sheep was ARQ/ARQ which is known to be susceptible to some
strains of scrapie and, in experiments, to BSE. Background information
on scrapie, scrapie genotyping, and the National Scrapie Plan is published
on the Defra internet at <http://www.defra.gov.uk/news/2004/../../nsp>www.defra.gov.uk/nsp>.
8. For information and advice on BSE in sheep from the FSA please consult
their website <http://www.foodstandards.gov.uk>
-
- ****** [3] Date: 6 Apr 2004 From: ProMED-mail <promed@promedmail.org>
Source: The Scotsman, 6 Apr 2004 [edited] <http://business.scotsman.com/agriculture.cfm?id=388482004>
-
-
- Concerns raised over fall in reported scrapie cases
- ---------------------------------------------------
-
- Farmers could be storing up trouble for themselves in
the next human food health scare by failing to report cases of the fatal
sheep brain infection scrapie. Although there is a legal requirement to
report scrapie, some state vets now believe that only happens for about
1 in 10 infected sheep and that more than 5000 flocks in the UK have had
at least 1 case, not the 500 or so recorded. It is also understood that
underreporting has become significantly worse in the run-up to a European
Union scheme this summer that can include whole-flock slaughter and no
sheep on a farm for 3 years. Unofficial figures indicate that during a
period when, on average, reports of about 100 cases of scrapie were expected
in the UK, there has been 1.
-
- The long term problem with underreporting is that scrapie
is a transmissible spongiform encephalopathy similar to BSE in cattle that
has been linked with more than 130 cases of the fatal human variant CJD.
Since BSE was identified as a human health risk more than 8 years ago,
the possibility that scrapie might be "masking" BSE in sheep
has been raised several times.
-
- 5 years ago this Apr, SEAC said: "There remains
the possibility that BSE in sheep might behave like scrapie and have been
sustained in some sheep." It made 20 recommendations for further research
and surveillance and media headlines at the time included the possibility
that the UK's 35 million to 40 million sheep might all be slaughtered and
incinerated.
-
- There have been several scares since then -- not helped
by 1 botched large-scale test that mixed sheep brains for analysis with
those of cattle -- and another "BSE in sheep" alarm always seems
imminent. As well as testing hundreds of sheep brains for any sign of BSE,
a national scrapie plan was introduced with the clear intention that if
scrapie were eradicated, the possibility of it hiding BSE would be removed.
The voluntary scheme concentrates on encouraging breeding only from ewes
and rams showing genetic resistance to scrapie and slaughtering those that
are susceptible.
-
- On 5 Apr 2004, the latest development in this scheme,
run by DEFRA, was announced, and is open to farmers who have had a case
of scrapie confirmed since July 1998. Being accepted for the "voluntary
scrapie flocks" scheme will provide free genotype tests, compensation
for culled animals and assistance to buy scrapie-resistant rams. About
90 Scots flocks could be eligible, more than half of them on Shetland.
The island virtually has a "closed flock" health policy and apparently
the highest incidence of scrapie in Scotland, almost certainly because
its farmers have been working to eradicate the disease for 20 years and
all cases are reported.
-
- [byline: Fordyce Maxwell]
-
- -- ProMED-mail <promed@promedmail.org>
-
- [The Scotsman's item [3], published one day before DEFRA's
news release, underlines the importance of improved reporting. At present,
there is no indication that BSE has infected sheep in field conditions,
but such a scenario has not been refuted. One may assume that the reporting
quality in other countries is similar to that of the UK. For background
on BSE and sheep, the reader may refer to postings 20021119.5847 and 20020106.3180.
- Mod.AS].
-
-
- Patricia A. Doyle, PhD Please visit my "Emerging
Diseases" message board at: http://www.clickitnews.com/ubbthreads/postlist.php?Cat=&Board=emergingdiseases
Zhan le Devlesa tai sastimasa Go with God and in Good Health
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