Friday, January 15, 1999 Published at 11:42 GMT
Tonsil test for CJD
New variant CJD is believed to be linked to BSE in cows
Scientists have developed a test for CJD which could show the extent of the disease in the population.
The test also suggests CJD may be more infectious than thought and could be spread through routine surgery.
The test involves taking tissue from the tonsils and can be conducted on living people.
The findings could eventually mean scientists will be able to develop a test which could diagnose people with nvCJD as soon as they are infected.
But the findings also raise concern about infection caused by the rogue proteins that spread the disease and cannot be cleaned from surgical instruments no matter how thoroughly they are sterilised.
An abnormal form of the protease-resistant prion protein is thought to cause the breakdown of brain cells associated with nvCJD.
Prions reproduce in the tissues of the immune system, including the tonsils.
Because of the theoretical possibility that the disease could be spread by surgery to the infected organs Professor Collinge recommends that for such operations only disposable surgical instruments be used.
The infection can withstand high temperatures which make the usual sterilisation procedures ineffective.
"This is one of the reasons why John Collinge's test may be so wonderful. It will give use some insight into just how big that risk is. This is a very important finding," he told BBC Radio 5 Live.
He said: "It is no cause for alarm but I think it is prudent to consider whether any precautions might be necessary."
Thirty-three cases of nvCJD in the UK and one case in France have been confirmed since 1996.
The researchers also tested tonsil, spleen and lymph node tissues from patients who had died of the disease.
They found that all immune system tissue obtained from dead patients whose CJD had been confirmed by brain biopsies contained the rogue prion.
Tonsil biopsies of living patients found the tissue was positive for the prion in the three cases which were confirmed on death to have the disease.
This suggests it could present greater dangers of infecting people through blood tranfusions, organ transplants and tissue-sharing.
They believe the difference in progression may be due to the suspected root of exposure - through eating BSE-infected meat.
This could suggest that the people who have developed nvCJD have immune systems which are particularly susceptible to nvCJD.
The scientists believe they may eventually be able to develop a test which is sensitive enough to detect prion infection at an early stage of infection.
Professor Collinge, whose research is funded by the Wellcome Trust and the Medical Research Council, said: "This new test has already proven very helpful in the diagnosis of new variant CJD.
"While, unfortunately, we have at present no means to treat this dreadful disease, we can at least now provide a definite diagnosis at an earlier stage."
He said research needed to continue to identify whether it would be possible to detect the disease through a simple blood test.