DOCTORS are likely to face a major ethical dilemma over the introduction of tests for variant CJD which could become available within a few years, a leading expert has warned.

Scientists are racing to find a reliable methods to diagnose vCJD at an early stage as the disease can currently only be confirmed through post-mortem examinations of victims' brains.

But speaking ahead of a major international conference on CJD, Dr Richard Knight, director of the National CJD Surveillance Unit in Edinburgh, warned of "very difficult moral problems" as to how any test would be used in practice.

Among the concerns he raised was the dilemma of telling an apparently healthy person they are infected with vCJD, which can have a incubation period of decades and for which there is no known cure.

Another problem, he said, is that there are questions over whether a positive test would necessarily mean a patient would develop the disease.

The Decade Past, Decade To Come conference, organised by the CJD Support Network, will take place in London tomorrow, the 10th anniversary of the date that the UK government admitted there was a link between BSE and vCJD.

Knight, who is one of the speakers, told the Sunday Herald that claims that tests for vCJD were only a year or two away were "quite likely". But he warned that there would be major difficulties in putting these tests into practice in humans, especially when considering the impact a positive test for vCJD could have on a patient's life.

He said: "If you had a positive test people might say to you, 'We're not really sure what to do with you, but you had better not donate blood. And if you need an operation we are going to have to treat you in a special way.'

"Maybe if you apply for a mortgage, they aren't going to be very keen on you having life insurance.

"So it may have a huge impact - apart from the fact you are going to be very worried you might develop vCJD."

Knight also pointed to the fact that because vCJD has an incubation period of decades, it would be a problem trying to ascertain if a positive test for infection would actually lead to the development of the disease in a person.

"You have the test done and it is positive, " he said, "but you are perfectly healthy. The difficulty would be what does that mean? You would want some proof that this positive test is a real positive test and not a false positive.

"Of course, the only way that we have at the moment of determining that would be to follow you up and see whether you developed the disease. The incubation period for this disease can be 10, 20, 30 years, so it could be very difficult.

"Even if you get a technical test developed and technically validated, if you use it for screening bodily fluids like blood donations there could be really difficult moral problems surrounding how you use it in practice."

Finding a test to detect vCJD and BSE in apparently healthy humans and animals has proved elusive. Currently the disease can only be confirmed through examination of brain tissue, though cases in humans are diagnosed as "probable" on the basis of symptoms at the latter stages of the disease.

But last year, a team in the US claimed they had made a breakthrough in developing a blood test which could detect the prion proteins, which are thought to cause the brain disease, in the blood of animals.

Experts in Britain have also developed a heart test to detect vCJD which they believe could be available within five years, subject to raising the investment required. This test uses a sophisticated ECG test, which is then analysed by a computer to detect the signature pattern of vCJD in humans or BSE in cattle.

Adrian Presbury, managing director of TSEnse Diagnostics, which has developed the test, said it could be used in a number of ways, including screening blood donors for the disease.

"The technology could be used for monitoring people who have had blood transfusions who are thought to be at risk, to maybe give them some comfort there is nothing abnormal there, " he said. "In the longer term it could be used as a routine test either prior to people having operations, who might be at risk of contaminating the instruments, or people giving blood."

But Presbury acknowledged that if this new technology was used for screening blood, there would be difficulties over the issue of whether to tell donors they had a positive test for vCJD.

He said: "The balance is that, if they are giving blood, they are passing it on potentially to a lot of other people. So there are ethical difficulties, but only what we all had to deal with with Aids - there is treatment for that now, but there wasn't originally. Whether you just keep taking the blood and throw it away or whether you tell them there is a problem, I'm not sure."

MEDICAL ethics expert Dr Hugh McLachlan, of the centre for ethics and public policy at Glasgow Caledonian University, agreed there was no obvious solution to the problem. But he added: "If blood donors ask, then I think they [doctors] should pass on what information they have. But they're not obliged to pass on that information without being asked."

A spokeswoman for the Scottish National Blood Transfusion Service said donors would be informed if a screening test for vCJD was introduced. She said discussions were still ongoing but it was likely, as with other tests, that donors would be told of the outcome.

The problem of transmission of vCJD through blood has emerged as a major concern in recent years. In 2003, the government announced the first case of a patient developing vCJD thought to be linked to receiving blood from an infected donor and a further two cases have since been identified.

A number of precautionary measures have been introduced, including banning recipients of blood transfusions since January 1980 from donating blood. But thousands of people in the UK, mostly haemophiliacs, are already living with a potential death sentence, after being informed they are at risk through receiving blood products from infected donors.

Campaigners say that a reliable test for vCJD is desperately needed to end uncertainty and to improve treatment for sufferers.

Graham Steel, of the CJD Alliance, said: "We are very close to finding a non-invasive 'live test'.

"If [the authorities] go that extra mile, we should be in a position to test asymptomatic carriers, which would make it practicable to truly focus on effectively treating these diseases at the earliest possible stages."

Gillian Turner, national co-ordinator for the CJD Support Network, said people had a right to know if they could have been exposed to vCJD infection, but added: "There is this ethical dilemma that if they are told, you are basically giving them news that there is no answer to, as there is no test in life for CJD and there is no treatment.

"What it all indicates is that we are in desperate need of a simple test for CJD and screening tests for blood."


THE FACTS Experts are warning of ethical dilemmas over vCJD tests.

BACKGROUND Since the 1980s, there have been 154 confirmed or probable deaths from vCJD in the UK, with a further six victims alive today.


www. cjd. uk


Jonathan Simms, 21, from west Belfast, was struck down with vCJD at the age of 17. He has become the longest known survivor of the disease after his family fought an eight-month court battle to allow an experimental drug treatment called pentosan polysulphate to be given to him.

But his father Don believes there is still a vast lack of knowledge about vCJD.

"Nobody really understands what the disease mechanism is, " he said. "We're 10 years on, millions of pounds spent and we are still in the dark.

"The sorry fact is that we don't know the incubation period and, without any form of testing, who is to say people aren't being misdiagnosed? Without an early diagnostic test, the damage is done.

Unless you have that test implemented, any treatment will get the same results."