BSE: Other TSEs - Creutzfeldt-Jakob Disease (CJD)
Creutzfeldt-Jakob Disease (CJD) was first described in Germany in 1920. CJD is a rare disease of worldwide distribution which occurs mainly in the 5th and 6th decades of life with an annual incidence of about 1 case per million. There is no significant association with occupation, place of residence or eating habits.
CJD link
More than 2 centuries’ experience with scrapie in sheep indicates that there is no link between CJD and eating sheep meat. Indeed CJD has been known to occur in lifelong vegetarians and occurs at the same rate in the UK as in countries such as Australia which are free of scrapie and BSE.
Incidence
All cases of CJD are intensively studied by the CJD Surveillance Unit which publishes an annual report. The number of cases fluctuates slightly from one year to another, although there has been a slight increase in incidence in recent years, which is not related directly to BSE. The more intensive surveillance carried out since 1990, has meant that more cases are being identified, especially in older patients (>70 yrs) who may previously have been diagnosed as suffering from senile dementia. The bulk of the increase is therefore attributed to improved case ascertainment. The same is experienced in many other countries that have improved their surveillance.
CJD is predominantly a sporadic disease but about 14% of cases are familial and associated with genetic mutations. Less than 1% are iatrogenic (accidentally transmitted from man to man as a result of medical or surgical procedures).
Variant Creutzfeldt-Jakob Disease (vCJD)
The National CJD Surveillance Unit recently identified a previously unrecognised form of CJD. The disease has appeared in recent years in patients under the age of 50. That is younger than typical CJD cases, which usually occur in late middle age. These cases had unusual clinical features including longer duration of illness and psychological change along with a distinctive appearance of plaque deposition in the brain.
vCJD Link
In March 1996 the independent Spongiform Encephalopathy Advisory Committee (SEAC) considered the first ten cases of the new form of CJD described by the CJD Surveillance Unit. The Committee concluded that the Unit had described a previously unrecognised and consistent disease pattern.
An in-depth review of each of the cases and consideration of other possible causes failed to provide an adequate explanation of this new form of CJD. In the absence of any credible alternative, in March 1996 SEAC concluded that the most likely explanation is that these cases were linked to exposure to BSE before the introduction of the Specified Bovine Offals ban in 1989.
For further information try the SEAC, CJD Surveillance Unit and Department of Health websites.
Page last modified:
12 July 2004