A method of detecting CJD on scalpels and other surgical instruments has been developed by UK scientists.

Scientists have found a way to spot even minute amounts of the prion protein which causes it on the metal surface of the instruments.

Fears remain that many thousands of people are harbouring prion proteins in their body, even if they have not yet developed the symptoms of vCJD.

When these people go in for routine operations, it is theoretically possible, although highly unlikely, that traces of the proteins could persist on re-useable surgical implements, even after they have been sterilised in the normal way.

Prion proteins can resist the conventional methods of decontamination, cleaning and sterilisation used for surgical instruments.

While the government has introduced new, higher standards of decontamination and cleanliness for these items, until now there was no effective way of checking to see whether these are truly working.

White light

The research team, from Southampton University, has come up with a way of checking equipment for traces of prions.

It uses fluorescent and white light - and claims it can pick out as little as a billionth of a gram of prion protein.

Professor Bill Keevil, who is leading the research, said: "Current epidemiological and research evidence suggests that the risk of infective prion transmission from CJD patients to other humans may be very low: nevertheless, infective prion agents constitute a serious biomedical hazard.

"For example, a proven but thankfully very rare route of infection involves contaminated surgical instruments, particularly those in contact with neural tissues.

"Our initial studies have shown our new fluorescent diagnostic procedures to be highly sensitive."

The same team is now working to produce a chemical test for the presence of prions on surgical implements.

A patent application has been lodged on the technology.