Andrew Yates in London
and Stephen Vines in Hong Kong report.
Nycomed is considering legal action over suggestions that one of its products had encouraged the spread of CJD. The problem arose after traces of possible contamination were found in the fluid given to more than 100 patients undergoing scans and gastric tests for heart and lung diseases. Seven of these people have since died.
Nycomed withdrew the Pulmonate kits after it suspected that they could contain blood extracted from a CJD victim which was mixed in with other blood to form albumin.
This is a protein extracted from blood which is part of the liquid injected in patients to assist in tests for various heart and lung diseases. However it is still not known how exactly CJD is transmitted and there is no known case of transmission through blood.
A Nycomed spokesman said: "There is no evidence that CJD can be transmitted by blood. There is not the remotest possibility that these seven people could have died of CJD even if our products were riddled with it. This has caused damage to us and is quite without foundation. We are lining up the lawyers."
Nycomed's shares fell 25p to 2370p yesterday after the story broke in Hong Kong overnight.
It remains unclear how the contaminated blood came to be used in the kits but it is more than likely that the blood donor was unaware of the infection. The kits were used in Hong Kong between July and December of last year. None of the patients have reported signs of illness.
The Hong Kong authorities did emphasise that the warning to patients who have used the kits was "purely a precautionary measure". The amount of CJD contamination was not proven, they said, and there was an extremely low chance of infection. Nevertheless they decided to go public "after balancing patients' rights to know and the possibility of causing undue anxiety to them".
Nycomed is highly critical of the decision. "We regret the public alarm in Hong Kong. It has probably caused a greater threat to public health than could ever be caused by our products and CJD," said the spokesman.
When CJD takes hold it causes fatal nervous disorders and more than 20 people in Britain have already died from this illness. However the incubation period for CJD is 10 years, and it can take up to 30 years to develop.