December 27, 2002 Manchester Evening News
MEDICS at Manchester Royal Infirmary have developed a painless,
10-minute test that can detect the human version of
mad cow disease up to five years before symptoms develop. The
test already appears to work in cattle by detecting subtle
changes in the heart rate linked to breathing and a leading
professor has called for everyone to be tested.
But Creutzfeldt-Jakob disease is incurable and fatal, so would you want to know if you were incubating a disease you could do nothing about? I considered these questions as I volunteered for the test as part of a special trial.
The test is very simple and involves having sticky pads on your chest to monitor your heart rate as you breathe through a mask. It sounded easy - it wasn't as if it involved needles or anything. So as my heartbeat began to show as blips and peaks on the monitor, why was I so nervous? What if the test was positive? Would I go slowly mad, develop dementia and suffer a painful, lingering death? I'm no hypochondriac, but I have always eaten beef, even through the height of the BSE scare. It is possible, according to some doctors, that you can have the disease for up to 40 years without showing any signs. Anyway, if I did have it I decided it was better to know.
Then research assistant Laura Woolfson said she wouldn't be able to tell me the results as it was part of a trial - that was going to be even worse. But she reassured me that if she found something that worried her when she analysed the test she would call me to arrange further tests.
The test, funded with a GBP 53,000 grant from the department of health, has been devised by Prof Brian Pollard and Dr Chris Pomfrett, who both work in the anaesthesia department at the MRI. They adapted a machine to check how deeply patients are anaesthetised before surgery. It measures changes in heart rate which show if an important nerve connected to the brain has been attacked, as it would be by vCJD.
If cleared by the government it could prove an easy and effective way of screening large number of patients, especially as Nobel prize-winner Prof Stan Prusiner, who discovered the cause of BSE, is calling for the whole population to be tested. vCJD has killed 117 people since 1995 and another 11 are dying. Some experts believe the death toll could reach 100,000.
Prusiner claims a million cattle infected with BSE entered the food chain which means almost everyone who eats beef will have been exposed to the indestructible prions that cause the disease. Even more worryingly Prusiner says sheep and cows carrying the disease, but not yet showing signs, could still be entering the food chain. He says we are simply killing them before they show symptoms. So with all this weighing on my mind, I breathe deeply into the mask and watch the monitor. But the machine is giving away no obvious signs, the data will take weeks to analyse.
Mrs Woolfson said: "It is very much up to the individual patient whether they want to know if they have it. Some would quit their jobs and travel the world and others would want to put their house in order before the mental problems set in. "The test has proved very effective in cattle and those fed just one gram of infected material came back positive, even though they were showing no outward symptoms."
The only definitive test so far is to take a tissue sample from the brain but other labs are working on blood tests which detect the dangerous prions. Mass testing would have public health benefits too, as patients can be prevented from giving blood and any surgical instruments used on them would have to be destroyed as the prions are resistant to high temperatures and chemicals. A spokesman for the CJD Support Network said: "What we really want is an early diagnostic test that can be done in life that is accurate. At the moment the only completely accurate test is done post mortem."
So as I sit and wait for the phone to ring, do carry on eating beef? Yes. Chances are if I'm going to get it, I already have it. And soon I'll know one way or the other.