A BRITISH company appears to have made a breakthrough in developing a test that can identify vCJD in people while they are still alive.

Until now it has not been possible to positively establish that a person has vCJD until after their death. This has meant that it has not been possible for health authorities to effectively screen blood and tissue donations for contamination with the virus.

In March the government announced a ban on blood donations from people who had themselves received blood before 1980 after it emerged that a man had contracted the disease after a blood transfusion donated by a man who later developed vCJD but was asymptomatic at the time of donation. The government says it took the step as a “precautionary” approach as it is still not possible for public health officials to determine whether this was the primary source of infection.

The new test, developed by the London-based company Microsens, was originally developed for post-mortem use in animals. However it emerged that the test might also be accurate in identifying the rogue prion thought to be responsible for vCJD in human blood samples. The company subsequently tested two patients thought to be suffering with the disease. The first patient tested positive, and continues to deteriorate, the other tested negative and later recovered – having appeared to have been misdiagnosed.

The news emerged days after it was announced that possible treatments for CJD are to be the subject of a new fast-track trial ordered by Department of Health officials. The study will focus on a range of experimental treatments for the range of Creutzfeldt-Jakob diseases, including vCJD.

These will include a trial of quinacrine, originally ordered by ministers in 2001. Pentosan polysulphate, a drug injected into the brain and first used to treat a Belfast teenager in 2002, will also come under investigation.

Other new tests for vCJD could also be considered. An electrocardiogram system developed by Manchester neuro-physiologist Dr Chris Pomfrett, has had some success on animals, but patients with the condition have not been avail-able for testing.

The announcement came on the same day that new research was published, finding that more people could be harbouring traces of vCJD than previously thought. A study of 12,674 appendix and tonsil samples by Plymouth’s Derriford hospital and the CJD Surveillance Unit found that three showed signs of the disease.

Extrapolated across the whole population, it is now estimated that as many as 3,800 people could be “carriers”.

“Our findings need to be interpreted with caution, but cannot be discounted,” said lead researcher David Hilton.

“There is still much to learn about vCJD and presence of the protein in these tissue samples does not necessarily mean that those affected will go on to develop vCJD.”

Professor James Ironside of the National CJD Surveillance Unit said patients might carry vCJD prions without showing any symptoms.

“That may be because of genetic differences and susceptibility, but it may also be that you can have a sub-clinical infection which never progresses to produce symptoms – a ‘carrier state’,” he said.

“I think the findings do have to be taken seriously. Generally, one has to be cautious about interpreting these data, but they may indicate that there are people who are not infected in the normal way, but could represent a source of infection.”