PRO/AH> BSE testing, humans - UK

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Date: 1/21/99 12:10:27 AM Eastern Standard Time

BSE TESTING, HUMANS - UK

A ProMED-mail post

http://www.healthnet.org/programs/promed.html>

[see also:

CJD (new var.), projections - UK 981214134320

CJD (new var.) - UK: 1990-1998 981207143647

BSE/CJD (new var.) & blood - UK (08) 981127001246]

Date: Wed, 20 Jan 1999 10:32:22 -0600

Source: Various News agencies (edited)

[For clarity, BSE = Bovine Spongiform Encephalopathy, CJD =

Cruetzfeldt- Disease, nvCJD = new variant Cruetzfeldt- Disease,

PrPsc = infectious prion. - Mod.TG]

The Lancet has the full text of *Investigation of Variant

Creutzfeldt- 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 Collinge, of St '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- 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 son, 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 £21.5

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 £120 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

e-mail: promed@...

[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

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