Creutzfeldt-Jakob disease not transmitted in donor blood

"This doesn't completely lay the issue to rest," Dr. Kumanan Wilson from the University of Ottawa, in Ontario, Canada told Reuters Health. "But the best evidence at this time from these and other studies suggests there is no link between blood transfusions and CJD."

"Based on our findings, we believe the position of the Canadian blood supply system--that it's okay to use blood from CJD patients--is a reasonable one," Wilson added.

However, the results can not be generalised to variant Creutzfeldt-Jakob disease (vCJD), the type of CJD some experts associate with eating meat from cattle with bovine spongiform encephalopathy (BSE) or "mad cow" disease. More than 50 people have died from vCJD in the UK and those cases are thought to be the result of an outbreak of BSE in cattle in the 1980s and early 1990s.

That type of CJD is unlike the 'sporadic' form looked at in the new study, according to the report in the July 1st issue of the British Medical Journal. CJD is marked by rapidly worsening dementia and by a death rate of more than 90% within 1 year of diagnosis. Although rare, the possibility of blood transmission of CJD raises concern because of the known transmission of diseases such as hepatitis and HIV by transfusion, according to Wilson and his colleagues. CJD can be transmitted by needles, instruments and electrodes that have come into contact with brain tissue of patients with the illness.

The research team reviewed five published reports of studies including 2,479 patients from around the world in an effort to determine whether there was an association between blood transfusions and the development of CJD.

People who had blood transfusions had no greater risk of developing CJD, and in at least one study, actually had a lower risk of developing the disease. Overall, recipients of blood transfusions had a 30% lower risk of developing CJD compared with those who had not received blood transfusions, the investigators note.

"This systematic review does not support an association between blood transfusion and development of sporadic Creutzfeldt-Jakob disease," the authors conclude.