Experimental data suggest that blood components from patients with CJD may carry infectivity. However, most of the studies have been made on the classic form of CJD. Further studies are needed to discern whether infectivity levels in blood from patients with the nvCJD differ from those with the classic form. Possibility of transmission of CJD by blood or blood products can not be excluded and therefore adequate surveillance should be implemented. People who have been exposed to contaminated blood should be followed, while recommendations are being adapted according to new scientific data on infectivity.