Creutzfeldt-Jakob disease (CJD) is a very rare condition that belongs among prion-related diseases. Prions are strange infectious particles that have been discovered in late 20th century. Prions are neither bacteria nor viruses; they are “just” proteins. They are able to reproduce themselves uncontrollably and that makes them similar to the common infectious diseases. Creutzfeldt-Jakob disease occurs in about one person from a million.
CJD is caused by formation of pathological protein deposit in the brain of the affected person. The reason is unclear; there is probably a genetic predisposition. Spontaneous occurrence is very rare and the disease is more frequently transmitted from infected human to another. The biggest risk is a contact with infected tissues in organ transplants and during neurosurgical interventions as prions may stay on surgical instruments used to operations of affected people.
Prion protein gets into the brain and behaves like a virus. It forces the brain cells to produce copies of prion proteins. These copies spread to other cells and the process expands. Cells filled with prion proteins burst and die. The disease manifests with a rapidly progressive disintegration of personality and dementia. The process could be compared to a quickly and severe form of the Alzheimer's disease. The symptoms include mobility disorders and hand tremor. The course of the disease is fatal and the affected person usually dies within months from the onset of the first signs.
The disease can be diagnosed only from the brain biopsy (taking a small sample of brain tissue and its examination).
Prevention of the primary CJD is not possible. However, it is possible to prevent the transmission by special sterilization of surgical instruments (especially in neurosurgery) as prions are quite resistant to the common ways of sterilization.
There is no treatment that can cure the patient. Creutzfeldt-Jakob disease is fatal in 100% no matter the treatment.
Similar prion diseases
There are some prion diseases that are similar to CJD. There is the quite exotic “Kuru-Kuru” that occurred in the Pacific where cannibalism has been practiced. The disease spread easily because the cannibals ate infected parts of human bodies (especially the brain). Given that the cannibalism was widespread in this location, Kuru-Kuru infected and killed a large number of people. The disease manifests itself like Creutzfeldt-Jakob disease and it was typical by bouts of uncontrollable laughter. Scrapie is a prion disease affecting sheep that is quite similar to the Mad cow disease. Mad cow disease or Bovine spongiform encephalopathy (BSE) is a prionic cattle infection. The cows get infected by eating infected meat and bone meal produced from crushed body parts of other cows. Humans get the disease similarly by eating meat of sick animals. In 1990s there was a great hysteria in the United Kingdom associated with a massive discharge of cow herds, but that has been probably not necessary. There is a certain interspecies barrier against the transmission of prion particles and that means that only a small percentage of people could get infected.