The first case of vCJD disease associated with blood transfusion was identified in December 2003 [3]. This patient developed vCJD six and a half years after receiving a transfusion of red blood cells donated by an individual who developed symptoms of vCJD three and a half years after donation [4].

Another case of vCJD 'infection' was identified a few months later in a recipient of red blood cells from a donor who developed symptoms of vCJD 18 months after the donation [5]. This second patient died from causes unrelated to vCJD five years after transfusion. Postmortem investigations found abnormal prion protein in the spleen and a cervical lymph node, but not in the brain, and no pathological features of vCJD were found [6].

The most recent patient developed vCJD almost eight years after receiving a transfusion of red blood cells from a donor who developed vCJD about 20 months after donating this blood [1]. Each of the three infected recipients received blood from different donors.

To date, 160 cases of vCJD have been identified in the UK. A collaborative study (the Transfusion Medicine Epidemiology Review) between the National Blood Services, the National CJD Surveillance Unit and the Office for National Statistics has been conducted since 1997 to collect evidence about transmission of CJD or vCJD via the blood supply [7]. Review of data at blood centres has found records for 23 of the 160 vCJD cases (prior to their vCJD diagnosis). For 18 of these 23 cases, blood components were issued to hospitals for transfusion, and 66 recipients of these vCJD-implicated blood donations have been identified.* Forty of these 66 recipients have died, including the two previous patients with probable transfusion-associated vCJD [4,6]. The small group of living recipients of vCJD-implicated blood transfusion have been informed of their potential exposure to vCJD by blood transfusion. Some were contacted in late 2003 and early 2004, and some in 2005. They were asked to take certain precautions to reduce the risk of onward person-to-person transmission of vCJD during medical procedures.

All three infected recipients identified to date received non-leucodepleted red blood cells. Since October 1999, leucocytes have been removed from all blood used for transfusion in the UK. The effect of leucodepletion on the reduction of the risk of transmission of vCJD from an infected donor is uncertain.

The risk of vCJD infectivity in blood has also resulted in certain other groups of individuals being categorised as ‘at risk of vCJD for public health purposes’. These groups have been informed and asked to take public health precautions. The groups include certain recipients of plasma products [8], individuals who have donated blood to patients who developed vCJD [9] and certain recipients of blood from donors to patients who developed vCJD [10]. To date, there have been no vCJD cases associated with receipt of plasma products, or in these other groups of individuals that have been categorised as ‘at risk’.

This third case of vCJD infection associated with blood transfusion provides further evidence that vCJD can be transmitted between humans by blood transfusion, although much remains unknown. This reinforces the importance of the existing precautions that have been introduced to reduce the risk of transmission of vCJD infection by blood and blood products [11].

Numbers of vCJD cases countries other than the UK remain small: by January 2006, there had been 15 cases reported in France, 4 in Ireland, 2 in the United States, and 1 each in Canada, Italy, Japan, the Netherlands, Portugal, Saudi Arabia and Spain [12].

*Correction. There was an error in this article as originally published on 9 February. The original text from the beginning of the paragraph until the asterisk read 'To date, 160 cases of vCJD have been identified in the UK. Of these, 23 are known to have donated blood before the diagnosis of vCJD. A collaborative study (the Transfusion Medicine Epidemiology Review) between the National Blood Services, the National CJD Surveillance Unit and the Office for National Statistics has been conducted since 1997 to collect evidence about transmission of CJD or vCJD via the blood supply [7]. Blood donations have been traced for 18 of the 23 known donors, and 66 recipients of these vCJD-implicated blood donations have been identified.'

This was an incorrect description of the study results, and the mistake was corrected in both Eurosurveillance, and the CDR Weekly article (reference 2) on 16 February 2006.
Eurosurveillance Editorial Office

This article has been adapted from reference 2