Creutzfeldt Jakob Disease or Human Spongiform Encephalopathy

Generalities
Agent	- Abnormal form of self-replicating host-encoded protein or prion protein - 4 forms: sporadic (sCJD), iatrogenic (iCJD), genetic (gCJD) and and new variant (vCJD)
Incubation period	- For iCJD: 15 months – 30 years - For vCJD: may be 6-9 years
Period of transmissibility	As long as prions are present, found in lymphoid tissues from early incubation, and lately in the Central Nervous System CNS
Reservoir	- For sCJD, iCJD: Humans - For vCJD: cattle affected with Bovine Spongiform Encephalopathy (BSE)
Modes of transmission	- sCJD: unknown - iCJD: transmission from sCJD via human pituitary hormone therapy, human dura mater grafts, corneal grafts, neurosurgical instruments - gCJD: hereditary mutation on chromosome 20 - vCJD: blood transfusion, hypothesis of consumption of food from animal infected by BSE agent
Clinical presentation	- sCJD and iCJD: subacute spongiform encephalopathy (confusion, progressive dementia, ataxia, myoclonic jerking...), with typical Electro-encephalogramm (EEG), fatal within 3-12 months - vCJD: subacute spongiform encephalopathy in younger age group, without typical EEG, with longer clinical course and behavioral disturbance - gCJD: Fatal Familial Insomnia (FFI), Gerstmann-Staussler-Schneiker Syndrome (GSSS) - Case fatality: 100%
Resources
Case definition	- MOPH circular no. 42 (2007) - MOPH circular no. 44 (2007): new variant
Forms	- General reporting form - CJD investigation form
Data	Refer to "Surveillance data" webpage