Jiglu: Farmtalking: Discussion: Sheep injected with BSE

Originally from: Farmtalking

From: ...

Originally from The Scotsman –

http://www.thescotsman.co.uk/business.cfm?is=1284292002

Scientists discover sheep can get BSE. No need to panic, they say. Should we?

A SHEEP of a type thought to be resistant to BSE has developed a similar type of infection.

Elliot Morley, the minister for animal health, moved swiftly to downplay fears.

He said that the infected sheep was the only one to develop a disease from a group of 19 which had been subjected to a "massive and unnatural" injection of BSE-infected material directly into their brains.

The experiment was carried out by the government-funded Institute of Animal Health at Compton, Berkshire, as part of a £20 million programme of research into transmissible spongiform encephalopathies (TSE) in sheep.

Mr Morley said: ‘‘It has been known for some time that sheep can be infected with BSE under experimental conditions. This result, if confirmed, will tell us nothing more than we already know about the possibility of BSE in the national flock.

"In spite of this result, the fact remains that no sheep of this genotype has been found with a transmissible spongiform encephalopathy in natural, non-experimental, conditions."

Other experts were also quick to soothe public concerns.

George Milne, a development officer with the National Sheep Association in Scotland, said: "This is a research finding in totally artificial circumstances. It has no relevance whatever."

A sheep veterinary specialist said that, with the doses being injected under such artificial conditions, he was surprised that only one of the 19 sheep involved in the experiment became infected.

Although BSE in sheep on farms has never been found, the concern for the government about the possibility is the probable link between the cattle brain infection BSE and the fatal human condition Creutzfeldt-Jakob disease which was made in 1996.

It is now believed that more than 120 people have died from new-variant CJD caused by BSE-infected cattle reaching the human food chain.

Every new revelation about BSE causes a public tremor, no matter how much every organisation and scientist involved tried to play down the appearance of BSE in a single sheep.

Too many members of the public remember a succession of government denials that BSE could have any effect on human health from the late Eighties until the cataclysmic admission in March 1996 that there was a probable link.

As far as the public is concerned, the shorthand of yesterday’s report is that the most resistant of sheep can get BSE, no matter how they get it.

The explanation of why it is extremely unlikely to happen under normal farming conditions, and why a case of BSE has never been identified in Britain’s more than 30 million sheep, takes longer.

It begins with scrapie, a disease of the sheep’s brain and nervous system which has been known for at least three centuries and has never been linked to human infection of any kind.

Nor had there been any serious concern about it. Shepherds knew that some breeds and some flocks within breeds were more susceptible than others, but, as with a range of other diseases, shepherds tended to bury their problems.

BSE changed that. If a TSE in cattle – caused by no-one knows precisely what, except that it is a tiny prion of protein of some kind – could jump species and kill humans, could the same happen with sheep?

There was no record of scrapie ever having killed anyone. But it is very similar to BSE. Could the harmless scrapie be masking the presence, in some sheep, of the much more dangerous BSE?

Laboratory testing began. Tests of sheep brains from slaughterhouses ended in fiasco last year when it was found that scientists had confused containers of sheep and cattle brains. More solid scientific work, funded by the Department of Food and Rural Affairs as part of a £20 million research programme into transmissible spongiform encephalopathies in sheep, has been more successful.

In one experiment five years ago, five grammes of BSE-infected material was fed to genotype-resistant sheep. None has developed BSE.

The work also includes a national scrapie plan for the UK, at present voluntary, designed to eradicate the disease which would, as a by-product, make any future identification of a TSE in sheep easier. More than 260,000 sheep have now been genotyped and more than 7,000 flock owners are taking part with another 11,000 expressing interest.

It is now seen as in everyone’s interest to eradicate scrapie. The plan and research work is based on the fact that 15 separate sheep genotypes have been identified, ranging from the most susceptible to TSEs to most resistant.

In an experiment with a susceptible genotype group, 17 out of 19 sheep succumbed to BSE after a direct injection with infected material and an average incubation period of less than 19 months. So the fact that sheep can be infected with BSE is not new, as Mr Morley was keen to emphasise yesterday.

He said: "It has been known for some time that sheep can be infected with BSE under experimental conditions. This result, if confirmed, will tell us nothing more than we already know about the possibility of BSE in the national flock."

The concern with the news is that the group of 19 were from the most resistant genotype group – ARR/ARR – bred from sheep imported from New Zealand where scrapie is unknown, even if the incubation period was more than 33 months, long past the age when most sheep are slaughtered to be eaten.

A report of the result has been given to the European Commission’s animal health committee, which is working on an EU scrapie plan.

It will also be considered by a sub-committee of the spongiform encephalopathies advisory committee on 11 December, which will report back to ministers on any possible implications for the national scrapie plan.

Trouble on the farm: a disease factfile

What is Bovine Spongiform Encephalopathy?

A brain and nervous system disease in cattle which was first identified in 1986. Ten years later, it was linked to the human brain infection, Creutzfeldt-Jakob disease. More than 120 variant-CJD deaths so far have been linked to eating BSE-infected meat before stringent controls were introduced.

What is scrapie?

Scrapie in sheep shows similar symptoms to BSE, but was first identified three centuries ago and has never been linked with any human infection even when potted head and sheep’s-head broth was a regular part of the British, especially Scottish, diet.

Can sheep get BSE in normal farming conditions?

Not as far as we know. But the concern is that the infections are so much alike – the precise cause of these and other transmissible spongiform encephalopathies has never been established – that scrapie could be masking BSE.

But sheep can be infected with BSE under experimental conditions?

Almost any species could, theoretically, be infected by massive doses of BSE-infected material injected directly into its brain. It could be argued that only one animal out of 19 getting the disease has indicated the strength of that genotype’s resistance.

What would happen if a sheep was found to have BSE under normal farming conditions?

It would be devastating. Several million cattle have been slaughtered and burned to prevent them reaching the human food chain during the BSE eradication programme since 1996, and a similar operation would have to be implemented for sheep.

Should sheep farmers and the public be optimistic?

Yes. More than ten years ago, it was proved that pigs could be infected with BSE if a big enough injection of infected material was used. There has never been any question of pigs having BSE under natural conditions.

Originally from: Bill

The sheep in this latest experiment were bred from a BSE resistant strain from New Zealand where there is no scrapie. Why would that be I wonder, anything to do with high copper content in the N.Z.soils?

The offspring (which I believe were first generation) would have been born with a good supply of copper from the mother and only one out of nineteen is alleged to have developed the "disease" which is still not proven as communicable. (You could inject high concentrations of cancer cells and get the same result)

Does anyone know where I can access a distribution map for scrapie or BSE in the U.K. so I can compare it with a soil map.

Bill.

Originally from: Farmtalking

Hi Bill! –
Try taking a look at –

http://www.markpurdey.com/science_the_origins_of_bse.htm

It includes a map of the UK and CJD incidence.

Best wishes – Jane

Originally from: David

Bill,

Top of my head but is there not more scrapie in upland sheep areas (poor soils) whereas BSE hit the national dairy herd – good soils.

David

Originally from: frances fish

But Scrapie is not BSE is it ? Neither, despite their best efforts, is vCJD BSE. All of these conditions ( I still do not refer to them as diseases !) are seperate to their species and, to my mind, are not interchangeable. So unless and until there are shady characters lurking in the countryside armed with cordless drills ( to make the hole in the skull ) and a syringe full of BSE contaminated bovine brain (to inject it directly into the poor innocent ovine individual ), I think we can safely say that it is unlikely that sheep get BSE through natural means. Which scientist thought up this particularly sick experiment anyway ? Who authorised the "research" ? How is/was it being funded ? What was the objective , to prove sheep could get BSE, however bizarre the route ? A face-saving excersize for the infamous sheep brain research but oops, sorry, its cow brain !!! Yet Defra "missed " the deadline for funding into TSE related work. By design ? By sheer incompetence ? Anyone's guess. The more one learns about this whole issue ( and I mean TSE's ), the more its apparent that so little is known and so much more is there to be discovered, don't you think ? Until this happens or doesn't,no-one should be jumping the gun. Frances

Originally from: Farmtalking

I rather think you've 'hit the proverbial nail on the head' there Francis! – Best wishes – Jane

Originally from: Bill

'Good' soils can still be mineral deficient. I am interested in what relationship there is between soil type and incidence of these 'diseases', if indeed any of them are transmissible diseases.

All the reference books say scrapie is a transmissible disease but with so-called 'long incubation periods' could it not be a degenerative disease? Who did the research and where were the findings published?

There is not one single shred of evidence to link Scrapie with either BSE or vCJD despite the Government's best efforts. There is not one single shred of evidence linking BSE to vCJD and yet we are supposedly going to slaughter the entire National sheep herd if a single case of BSE is found in sheep.

The lunatics are running the asylum and without the benefit of a 20 million quid research budget I am trying to find an alternative explanation to present to the lunatics.

Surely somebody has got scrapie and BSE distribution maps.

Bill.

Originally from: Joyce

Bill, I am sure there is a suitable map on the Mark Purdey link that Jane gave a day or so ago.
Joyce

Originally from: Bill

Frances, I read somewhere (I think on the original posting for this topic) that the Government have allocated 20 million quid to this dubious ongoing research programme which, as you say, is a face saving exercise.

The difficulty is nobody wants to hold their hand up and admit to the biggest cock-up in human history.

Bill.

Originally from: Farmtalking

The link to Mark Purdey's article 'The Origins of BSE' which includes the comaparative map, etc. is here –

http://www.markpurdey.com/science_the_origins_of_bse.htm

Bill – If some messages are coming through to you blank take a look on the message board itself and there you can read them, now all listed in anew format under the subject title head of each one. There is also a search facility on the board too – although at times it's quicker to ask a question – it's amazing how quickly the answer appears from someone! Best wishes – Jane