The measure resulted in ten percent of New Zealands active blood donors at the time becoming ineligible to donate blood. In 2003, the NZBS further extended restrictions to permanently preclude donors having received a blood transfusion in the United Kingdom since January 1980, and in April 2006, restrictions were further extended to include the Republic of Ireland and France.Similar regulations are in place where anyone having spent more than six months for Germany or one year for France living in the UK between January 1980 and December 1996 is permanently banned from donating blood.In Canada, individuals are not eligible to donate blood or plasma if they have spent a cumulative total of three months or more in the UK, or France from 1 January 1980 to December 31, 1996.
The human PRNP protein which is subverted in prion disease can occur with either methionine or valine at amino acid 129, without any apparent physiological difference. Of the overall Caucasian population, about 40% have two methionine-containing alleles, 10% have two valine-containing alleles, and the other 50% are heterozygous at this position. Only a single person with vCJD tested was found to be heterozygous; most of those affected had two copies of the methionine-containing form. It is not yet known whether those unaffected are actually immune or only have a longer incubation period until symptoms appear. Diagnosis
Definitive
Examination of brain tissue is required to confirm a diagnosis of variant CJD. The following confirmatory features should be present:
Numerous widespread kuru-type amyloid plaques surrounded by vacuoles in both the cerebellum and cerebrum – florid plaques. Spongiform change and extensive prion protein deposition shown by immunohistochemistry throughout the cerebellum and cerebrum. Suspected
Current age or age at death less than 55 years (a brain autopsy is recommended, however, for all physician-diagnosed CJD cases). Psychiatric symptoms at illness onset and/or persistent painful sensory symptoms (frank pain and/or dysesthesia). Dementia, and development ≥4 months after illness onset of at least two of the following five neurologic signs: poor coordination, myoclonus, chorea, hyperreflexia, or visual signs. (If persistent painful sensory symptoms exist, ≥4 months delay in the development of the neurologic signs is not required). A normal or an abnormal EEG, but not the diagnostic EEG changes often seen in classic CJD. Duration of illness of over 6 months.