Blood Safety Surveillance and Health Care Acquired Infections Division Centre for Communicable Diseases and Infection Control

The new variant Creutzfeldt Jackob Disease (vCJD) is the human form of the mad cow disease or the Bovine Spongiform Encephalopathy (BSE). Both are subset of a larger group of neurodegenrerative disorders called Transmissible spongiform encephalopathies (TSEs). Those disorders are caused by non-conventional infective proteins called prions. Infective prions (PrPSc) are misfolded forms of the normal prion protein (PrP) that are expressed different tissues particularly the central nervous system. The etiology of vCJD has been linked to the consumption of BSE-contaminated beef. Other animal TSEs include chronic wasting disease (CWD) in the deer and elk population of the US and Canada, transmissible mink encephalopathy (TME) of mink, and other sporadic cases in domestic cats and zoo animals. Other forms of TSE in humans include the classical Creutzfeldt- Jacob disease (CJD) which occurs as sporadic, genetic and iatrogenic. A good review of these diseases can be found in Liberski, (2008) (1). Like BSE, vCJD is an infectious disease typified by long incubation period and asymptomatic infections, two factors making epidemiological investigations particularly difficult. Primary infections are associated with the ingestion of infectious materials. Secondary infections are associated with blood transfusions and surgical procedures