Letter to Dr Carolyn Millar from The Central Office for Research Ethics Committees accepting her amendment to the study Surveillance of new variant CJD-UKHCDOThe amendment reflected a change in the way UKHCDO collected data for the surveillance of vCJD in patientsPrior to 2004 the focus was on tracking the recipients of factor concentrates from batches that were known to have been recalledHowever following the discovery of further implicatedbatches a decision was taken to consider all patients with bleeding disorders who had received factor products between 1980 and 2001 were considered to be at-riskof vCJD.