Thousands of people could be infected with the human form of "mad cow" disease from blood transfusions each year because safeguards are inadequate, medical experts have warned.

The incurable disease, called variant Creutzfeldt-Jakob Disease (vCJD), could be spread from infected blood transfusions and blood products taken from people who are carrying vCJD without realising it.

The warning, by a panel of European experts on emerging diseases, is increasing pressure for the development of a fail-safe blood test for vCJD. At present, the blood transfusion service can only partly guard against the risk of infected blood passing into the healthcare system.

Worldwide, the disease has so far killed more than 150 people believed to have eaten BSE-infected beef, but there are two cases of victims who are thought to have received vCJD-contaminated blood transfusions. A third person believed to be infected by a blood donor has not so far fallen ill.

The committee, which reports to the EU Health Commissioner, Markos Kyprianou, has warned that up to 3,750 people a year may be given contaminated blood or blood products.