Babies and young children are to be treated with only imported blood to avoid them contracting the human form of mad cow disease from British plasma.

Youngsters born after 1995 are thought to have escaped coming in contact with variant Creutzfeldt-Jakob Disease (vCJD) in the food chain.

The Department of Health said the move was designed to stop them becoming exposed to vCJD which could potentially be carried in British blood products.

Although there is no evidence that vCJD has been transmitted through human blood, it is right that we should take this precautionary step

Hazel Blears Minister for Public Health

Earlier this month it emerged that the risk of the human form of BSE being transmitted through blood transfusions might be considerably higher than previously thought.

Tests at the Institute of Animal Health revealed one in six animals given blood from sheep infected with a similar disease went on to develop the illness, suggesting that there was an "appreciable" risk to humans, it was reported.

Public Health Minister Hazel Blears said: "Although there is no evidence that vCJD has been transmitted through human blood, it is right that we should take this precautionary step to protect those babies and young children born after 1 January, 1996."

White blood cells

She said the National Blood Service would be receiving fresh frozen plasma from unpaid American donors.

In addition, the blood would be bought in single units rather than in the form of pooled blood.

"This precaution is in addition to steps that have already been taken to minimise the theoretical risk of vCJD through blood and blood products," said Ms Blears.

"These include the removal of white blood cells which evidence suggests may carry the greatest risk of transmitting vCJD, and the importation of plasma from the US for the production of blood products."

Premature babies

Deputy Chief Medical Officer Dr Pat Troop told the BBC: "All the plasma products we used for people, for example who need clotting factors is already bought from the US.

"Our experts advice is that for this vulnerable group we should take one more step, and that is for the plasma itself to be bought from the US."

She added that the age had been set at six because it tended to be children under that age who were affected.

"The vulnerable group who tend to need this plasma tend to very young children who are in intensive care when they are very small."

A DoH spokesman added that the National Blood Service would be importing the product within the next nine to 12 months following negotiations to guarantee supplies.

Frances Hall, secretary of the Human BSE Foundation, welcomed the government�s decision.

She said: "Anything that aids in safety gets our full approval.

"It always has been a consideration that blood could be infected, and experiments on sheep have firmed this up, rather than the other way, so it is a precautionary measure which we approve of."

But she said it was "only a matter of time" before cases of vCJD occurred worldwide - including in Americans who had travelled to countries with a vCJD problem.

Mrs Hall, whose 20-year-old son Peter died of vCJD in February 1996, said each unit of blood should be checked before it was used.

She added: "I don't know how far off that is, unfortunately it does not exist yet. The long incubation period makes it difficult to detect."

Dr Evan Harris MP, Liberal Democrat Health spokesman, said:"Although today's announcement is welcome, the government decision to deny these products to the majority of the population who are over six-years old, along with the best technology to wash potentially infectious viruses out of the blood needs clarification.

"If the government is going to ration safety on the basis of cost, supply or risk reduction, it should be open and honest with the public about it."

Clotting

Plasma is the fluid in which the red and white blood cells and platelets are suspended and carried around the body.

It contains clotting factors, antibodies, albumin and minerals.

It is used to treat premature babies, and babies and children having heart surgery, liver transplants and after major accidents and injuries.

Plasma is also given to patients with blood-clotting problems and helps support people in intensive care units.