Blood transfer fear over CJD death
LONDON, England (Reuters) -- Britain announced Wednesday what could be the world's first possible case of the transmission of the human form of mad cow disease through a blood transfusion.
It is not certain whether the unidentified patient who died earlier this year had been infected through blood transfusion from a donor who later died of variant Creutzfeldt-Jakob disease (vCJD) but health officials said it could not be ruled out.
"This is the first report from anywhere in the world of the possible transmission of vCJD from person to person via blood," Health Secretary John Reid told parliament.
Variant CJD is the human equivalent of Bovine Spongiform Encephalopathy or mad cow disease, an incurable, degenerative brain disorder linked to eating meat infected with BSE.
Reid said the donor showed no signs of vCJD in 1996 when the blood was donated to the National Blood Service and given to the recipient shortly afterward. The donor developed the disease in 1999 and died from it. The recipient of the blood developed vCJD after a 6.5 year incubation period.
"It is ... possible that the disease was transmitted from donor to recipient by blood transfusion," Reid told parliament. "This is a possibility, not a proven causal connection."
It is also possible that both individuals separately acquired vCJD by eating BSE-infected meat or meat products.
"There is no way of deciding between these possibilities," Britain's Chief Medical Officer Sir Liam Donaldson told a news conference.
"A blood transfusion cannot be ruled out and must be taken seriously," he added.
Donaldson said that if the blood transfusion was the source of the transmission it means that the donor was infectious before displaying symptoms of vCJD.
Donaldson said 15 people in Britain have received donations of blood from donors who subsequently developed vCJD. He added that they will be contacted, informed of the risks and offered counseling. The earliest transfusion was in 1993 and the latest in 2001.
There is as yet no blood test for vCJD that can detect the disease years before symptoms develop. So there is no way of screening blood donations for the presence of the CJD group of diseases.
Britain took several precautionary measures to ensure the safety of its blood supplies in the late 1990s. All cases of probable vCJD are reported and if records show the patient had given blood, any stocks are immediately destroyed.
White blood cells, which are thought to be a potential source of infection, are removed from blood destined for transfusions. Britain also imports all plasma and plasma products from the United States, which is BSE-free. Last year it bought the U.S. company that is the major supplier of plasma and plasma products.
The actions were based on the assumption that blood could be infectious even if it is taken from symptom-free people who are incubating the disease.
Donaldson said health experts are looking at further measures to improve safety including reducing the use of blood clinically and different ways of collecting and processing it.
Up to December 1, 2003 there had been 143 cases of vCJD in the United Kingdom. The annual number of cases has fallen over the last three years.
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