Human Form of Mad Cow Disease Transmissable by Transfusion

LONDON, UK, December 23, 2003 (ENS) - A British patient who died from the human form of mad cow disease may have picked up the brain wasting illness from a blood transfusion. For the first time last week, British authorities acknowleged it is possible that variant Creutzfeldt-Jakob Disease (vCJD), a fatal spongy degeneration of the brain, can be transmitted from one person to another through donated blood.

European lawmakers are examining their options for protecting the public health after British Health Secretary Dr. John Reid revealed Thursday that a patient who received donor blood during an operation in 1997 developed variant CJD and died six years later.

European Commissioner for Health and Consumer Protection David Byrne said that all the circumstances surrounding "this tragic death" need careful examination before any firm conclusion could be drawn.

Mad cow disease, or bovine spongiform encephalopathy, kills cattle by attacking the brain and nervous system. The related human disease, vCJD, was first identified in 1996 in Great Britain where most cases of mad cow disease have occurred.

Most people who have developed vCJD have lived in the UK. As of December 1, there have been a total of 143 cases of vCJD in the UK, and some of these patients have donated blood. But until Thursday, scientists had no evidence that a recipient of this blood became ill with vCJD.

The link is still considered only a possibility as the person who died could have contracted vCJD from eating infected meat.

Dr. John Reid is British Secretary of State for Health. (Photo courtesy Northern Ireland Office)

"However, the possibility of this being transfusion related cannot be discounted," Reid said.

Reid said the blood containing the vCJD agent was taken long before the donor was diagnosed with the brain wasting disease.

The British National Blood Service (NBS) said the recipient involved in this case received a blood transfusion during surgery for a serious illness.

The transfusion took place in 1996, before various precautionary measures around vCJD that exist today had been implemented. "This is a single incident and it is impossible to be sure of the route of infection. However, the possibility of vCJD being transmitted by blood cannot be discounted," the NBS said in a statement.

The revelation has made it tougher for the NBS to encourage regular, new and lapsed blood donors to give blood in the run-up to Christmas. "Giving blood is safe – you cannot contract vCJD through giving blood," the service says.

The NBS said it is important to "balance the unknown risk of contracting vCJD through a blood transfusion against the risk of a patient not receiving the blood transfusion they require."

Fifteen other people in the UK have received blood from donors who went on to develop vCJD. All have been contacted and offered counselling, but no others have to date developed vCJD, which has a long incubation period.

The UK no longer sources plasma from its inhabitants, and as a further precautionary measure, has instituted removal of white blood cells from blood transfusions. Some countries have prohibited donations of blood from persons who have resided in countries with higher risk of mad cow disease such as the UK, Belgium, France, Germany, Spain, and Switzerland.

Blood transfusions are now safer than they were in 1996, the National Blood Service says. (Photo credit unknown)

At a meeting of the EU's Communicable Disease Network Thursday the UK representative was asked to provide detailed information so that all concerned could examine the issue.

The question of vCJD transmission via blood or blood products is under constant review by scientific committees. Many EU member states have precautionary measures in place to protect their blood supplies.

A meeting of the Working Group of the Blood Regulatory Committee in January is expected to consider the latest information available from the UK authorities.

On EU level, a law on the safety and quality of human blood and blood products entered into force in February, Byrne said. The deadline for the transposition into national law by EU member states is February 2005.

The law establishes comprehensive and legally binding standards for blood and blood products from donor to patient and for related medical applications.

Measures include requirements for testing, labeling and traceability of blood and blood products, for quality management systems in laboratories and other establishments handling blood and an EU wide surveillance system.

Currently, there is no specific blood test for vCJD, so blood banks cannot check their inventory for the disease. But the EU is financially supporting development of such a test.

The EU is also funding a long term project in which the risk of BSE transmission through transfusion of blood is being assessed, and in which the blood components harboring infectivity will be identified.

Research on therapies for vCJD is also supported by the EU, ranging from drug development to vaccination.

The nature of the BSE agent is still being debated, according to the World Health Organization, which says, "Strong evidence currently available supports the theory that the agent is composed largely, if not entirely, of a self-replicating protein, referred to as a prion."

The disease is transmitted through the consumption of BSE contaminated meat and bone meal supplements in cattle feed. Normally vegetarians, cattle would not eat meat and bone meal without human intervention.