A Creutzfeldt-Jakob disease agent (Echigo-1 strain) recovered from brain tissue showing the 'panencephalopathic type' disease.

We used histologic evidence of degenerative changes in both the gray and white matter of the brain to diagnose a patient as having the panencephalopathic type of Creutzfeldt-Jakob disease (CJD). This type of CJD is relatively common in Japan, but not in North America or Europe. We recovered a transmissible pathogen (Echigo-1 strain) from an autopsy specimen of the patient's brain and passed it serially in Hartley guinea pigs. After a long latent period, it caused degenerative changes, mainly in the thalamic area of the guinea pig brain. On the 4th passage, a substrain emerged with a short latent period. When cross-transmitted to Golden Syrian hamsters, this substrain induced severe degeneration in both the thalamus and cerebral cortex. We compare our results with those for other experimental CJDs produced by other types of this disease.