vCJD is a variant of the most commonly identified TSE in humans, classic (sporadic) Creutzfeldt-Jakob Disease (CJD). Scientific evidence supports a causal relationship between BSE outbreaks in Europe and vCJD. The disease vCJD is most likely caused by the ingestion of products contaminated with the BSE agent. There has never been a case of vCJD that did not have a history of exposure within a country where BSE was occurring. Patients with vCJD have primarily been younger and exhibit clinical signs of the disease longer than patients with classic CJD.