Thought this might interest you prion-watchers. Again, note the
moderator's comment at the end regarding farmers and the food
system.
peace
misha
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
BSE TESTING, HUMANS - UK
************************
A ProMED-mail post
Date: Wed, 20 Jan 1999 10:32:22 -0600
From: Tam Garland
Source: Various News agencies (edited)
[For clarity, BSE = Bovine Spongiform Encephalopathy, CJD =
Cruetzfeldt-Jacob Disease, nvCJD = new variant Cruetzfeldt-Jacob
Disease, PrPsc = infectious prion. - Mod.TG]
The Lancet has the full text of *Investigation of Variant
Creutzfeldt-Jacob Disease and Other Human Prion Diseases with Tonsil
Biopsy Samples* available to registered non-subscribers. It is too
long and complex to relay directly. It can be found at
<http://www.thelancet.com/newlancet/reg/issues/vol353no9148/article183
.html>.
The article may be summarized essentially as: Infectivity was present
throughout the body tissues in nvCJD patients. Infectivity was absent
in the body tissues in all other forms of CJD and neurological
disorders in patients. Infectivity throughout the body has serious
consequences for iatrogenic cases.
This suggests: new variant CJD is uniquely different from all other
forms of CJD, strengthening the supposition is has a different cause
(viz., BSE). The presence of infectivity in non-nervous tissue for
nvCJD suggests a similar effect for BSE and amplifies the likelihood
of foodborne passage. The presence in non-nervous tissue can be used
as a differential diagnosis of nvCJD vs. other CJD.
Animals studies have shown that spongiform encephalopathy diseases,
which include different forms of CJD, BSE in cattle and scrapie in
sheep, tend to reside in the lymph system before attacking the brain.
Tonsils are part of the lymph system. These findings suggest that
human tonsil biopsy samples may allow presymptomatic diagnosis of
nvCJD. Assuming sufficiently sensitive tests were available, then
PrPSc will be detectable in human tonsil within months of exposure to
BSE.
Professor John Collinge, of St Mary's Hospital, London, published in
The Lancet the results of a test on 20 patients suspected to have
human BSE, known as new variant Creutzfeldt-Jacob disease. The test
failed to detect the prion protein in 11 patients, whom do not have
the disease. The protein was in the tonsils of the remaining 9. Of
these, 3 have died and been confirmed by autopsy; 1 has died but no
autopsy was performed and 5 are still alive. The Medical Research
Council and the Wellcome Trust funded the research that shows the
tonsil test could detect the infectious prion protein in nvCJD cases,
but not the "classical" CJD. Professor Collinge said this shows how
the rogue prion protein behaves quite differently to CJD. Possibly
the oral route of exposure, presumed to be the route of BSE infection
of patients with nvCJD, results in a more pronounced lymphoreticular
phase. Therefore, lymphoreticular tissues from patients with kuru
would be interesting to study.
Prof Collinge, said that scientists plan to screen thousands of people
using the new tonsil test. A significant positive result would provide
early warning of a major epidemic to come and allow time for action
aimed at averting the disaster. An anonymous mass screening program,
planned for later this year, will rely on anonymous tissue donors,
tissue removed during routine tonsillectomies and appendectomies.
There are now 35 confirmed cases of nvCJD, which may have developed as
a result of people consuming BSE contaminated beef, but there are
fears that this might be the first signs of an epidemic . Attempts to
estimate the future course of the disease have been hampered by a lack
of knowledge and a suitable test for early diagnosis.
Prof Collinge admitted his concern about the possibility of nvCJD
being transmitted via infected surgical instruments. This had always
been a theoretical risk, but the conclusive evidence of tonsil
infection meant it was now a real possibility. Cost prevents
discarding expensive surgical instruments, said Professor Collinge. He
added: "There is no means of sterilising surgical instruments
adequately for prions. My own view of this is that we may need to
consider using more disposable instruments for certain procedures."
Professor Liam Donaldson, the Chief Medical Officer said, "Current
policy based on advice from the Advisory Committee on Dangerous
Pathogens published in April 1998 is when any patient with symptoms of
nvCJD, or suspected of having nvCJD, undergoes surgical operation, the
instruments must be removed so that they cannot be used again."
Experts from the Joint Advisory Committee on Dangerous Pathogens and
the Spongiform Encephalopathy Advisory Committee are considering the
surgical implications. They will be advising the Government on setting
up new guidelines on the use of disposable surgical instruments to
limit the risks to patients.
Acting on expert advice the Government has already introduced
leucodepletion - removal of white blood cells - for donated blood and
banned the use of British-produced plasma in blood products. There is
no cure for nvCJD at this time, but research has shown that a drug
used in America to treat cystitis may block its spread.
Following this new development with BSE in humans, Nick Brown,
Minister of Agriculture, announced his decision to make the beef
industry pay u21.5 million a year in meat hygiene charges for BSE
controls. The result was a clash with leaders of the farming groups.
They said the move made a mockery of the Government's u120 million aid
to farmers two months ago. The Ministry of Agriculture said it did not
know how much the charges would be in individual cases but they would
be based "on the current national hourly rate for employment of meat
technicians, meat inspectors and official veterinary surgeons".
Charges, to be imposed from March 29, will cover the cost of the Meat
and Hygiene Service's enforcement of controls in abattoirs and meat
plants to ensure that "high risk" cattle and sheep offals are kept out
of the human food chain. [If an animal does not show clinical signs,
is not from an infected herd, what makes them *high risk*? - Mod. TG]
Until now, costs of checks on specified risk materials, including
brain, spinal cord, tonsils and spleen, have been met by the taxpayer.
Ben Gill, president of the National Farmers' Union of England and
Wales, said: "Specified risk material removal is a public health issue
and the industry should not be expected to bear the costs associated
with it."
The Government has allowed the industry until Feb 12 to comment on the
charges - but the consultation process only covers the details. The
decision to pass on the charges has already been taken. [Then what's
the point in comments? - Mod. TG]
- --
ProMED-mail
[Although this is a tremendous advancement in testing and hopefully
someday treatment of nvCJD, it is unfortunate the government considers
it necessary to make the farmers responsible. Yoking the farmer with
the responsibility of this and imposing higher cost on an already
suffering industry could have grave consequences on the food supply. -
Mod.TG] ...............................tg/es
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Michele Gale-Sinex, communications manager
Center for Integrated Ag Systems
UW-Madison College of Ag and Life Sciences
Voice: (608) 262-8018 FAX: (608) 265-3020
http://www.wisc.edu/cias/
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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would look for yours on earth. --Bob Marley
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