|Fact sheet No 180: Variant Creutzfeldt-Jakob disease (vCJD) - Revised December 2000 (WHO, 2000, 4 p.)|
· The hypothesis of a link between vCJD and BSE was first raised because of the association of these two TSEs in time and place. More recent evidence supporting a link, includes identification of pathological features similar to vCJD in brains of macaque monkeys inoculated with BSE. A vCJD-BSE link is further supported by the demonstration that vCJD is associated with a molecular marker that distinguishes it from other forms of CJD and which resembles that seen in BSE transmitted to a number of other species. Studies of the distribution of the infectious agent in the brains of mice artificially infected with tissues from humans with vCJD and cows with BSE showed nearly identical patterns.
· The most recent and powerful evidence comes from studies showing that the transmission characteristics of BSE and vCJD in laboratory mice are almost identical, strongly indicating that they are due to the same causative agent.
· Intensive surveillance in 17 European countries has confirmed the high incidence of vCJD in the UK, the country with the largest potential exposure to BSE. France (with three reported cases) imported relatively large quantities of cattle products from the UK. The one case in the Republic of Ireland lived in the UK. Australia, Canada and the United States of America (all with extremely low potential exposure) have no confirmed reports of vCJD. For the final opinion of the European Union's Scientific Steering Committee on the Geographic Risk of BSE, please see: http://www.europa.eu.int/comm/food/fs/sc/ssc/out113_en.pdf
· In conclusion, the most likely cause of vCJD is exposure to the BSE agent, most plausibly due to dietary contamination by affected bovine central nervous system tissue.