Creutzfeldt–Jakob disease

A rare, rapidly progressive degenerative condition of the brain. Creutzfeldt–Jakob disease (CJD) is thought to be due to an infection with a prion (slow virus). This is similar to the agent that causes scrapie in sheep and bovine spongiform encephalopathy (BSE) in cattle. One main variant of CJD largely affects middleaged or elderly people and has no obvious cause. A second main variant, occurring in younger people, is associated with contamination during brain surgery or transplants from infected people, or treatment with human growth hormone or gonadotrophin hormones. Recently, a 3rd variant, called new variant (nv) CJD, that attacks people in their teens and 20s has been identified. NvCJD causes pathological changes in the brain similar to those seen in BSEinfected cattle. It is thought to be acquired by eating infected beef. Symptoms are similar for all variants. Progressive dementia and myoclonus (sudden muscular contractions) occur; muscular coordination diminishes; the intellect and personality deteriorate; and blindness may develop. As the disease progresses, speech is lost and the body becomes rigid. There is no treatment and death usually occurs within 2–3 years.