Home › Topics › Prion Diseases (CJD and Others)

Prion Diseases (CJD and Others)

GMJ News knowledge hub · last reviewed August 2026 · Georgian Medical Journal

SummaryStatisticsGlossaryGMJ newsFAQDocumentsOrganizationsResearch

Prion diseases — caused by the misfolding and aggregation of normal prion protein (PrPC) into an abnormal, infectious form (PrPSc) — encompass a group of uniformly fatal, rapidly progressive neurodegenerative diseases including sporadic Creutzfeldt-Jakob disease (sCJD — 1-2 per million/year globally), variant CJD (vCJD — linked to BSE bovine spongiform encephalopathy/mad cow disease, 232 confirmed cases predominantly in the UK), fatal familial insomnia (FFI) and Kuru (WHO). Prion diseases are unique in that the pathogen is entirely proteinaceous — containing no nucleic acid — making them resistant to all conventional sterilisation methods and raising unique public health challenges around surgical instrument decontamination.

Key messages

Proteins as pathogens — unique biology
Prion diseases are caused by misfolded prion proteins (PrPSc) — abnormal versions of the normal cellular protein PrPC. The pathogen is purely proteinaceous — containing no nucleic acid — making prions resistant to all conventional sterilisation methods.
Always fatal — no treatment
All known human prion diseases are invariably fatal — there is no treatment that halts or reverses progression. sCJD median survival is approximately 5-6 months from diagnosis; vCJD approximately 14 months.
vCJD linked to BSE — the mad cow disease story
Variant CJD (vCJD) — caused by consuming BSE-infected beef — caused 232 confirmed cases globally (predominantly UK) following the 1980s-1990s UK BSE epidemic. vCJD affects younger patients with psychiatric symptoms first and is distinct from sporadic CJD.
Sporadic CJD — 1-2 per million — most common
Sporadic CJD (sCJD) — accounting for approximately 85% of CJD cases — affects approximately 1-2 per million per year globally. Cause unknown — spontaneous protein misfolding. Presents with rapidly progressive dementia, myoclonus, ataxia and visual disturbance.
RT-QuIC — the key diagnostic advance
Real-time quaking-induced conversion (RT-QuIC) of CSF — an ultrasensitive assay detecting misfolded prion seeds — has transformed CJD diagnosis, with approximately 95% sensitivity and near-100% specificity in sporadic CJD.
Iatrogenic CJD — preventing transmission
CJD can be transmitted iatrogenically through contaminated neurosurgical instruments, dura mater grafts, cornea transplants and growth hormone (now synthetic). Single-use instrument protocols and donor screening prevent iatrogenic CJD.

Key statistics

1-2/million
annual incidence of sporadic CJD globally
WHO
232
confirmed vCJD cases globally (as of 2023)
WHO/UK prion surveillance
5-6mth
median survival in sporadic CJD
WHO
14mth
median survival in variant CJD
WHO
100%
case fatality rate — all human prion diseases
WHO
~95%
RT-QuIC sensitivity for sporadic CJD diagnosis
WHO/Lancet

Human prion disease types — relative frequency (% of cases)

Source: WHO. Sporadic CJD dominates; vCJD rare after BSE control; genetic forms relatively constant.

Glossary of key terms

PrPC and PrPSc
WHO/NobelPrPC (normal cellular prion protein): found on the surface of neurons; exact function unclear but may be neuroprotective. PrPSc (pathological misfolded prion): adopts a beta-sheet-rich conformation; aggregates into amyloid plaques; catalyses conversion of surrounding PrPC to PrPSc — the autocatalytic "infection" mechanism. Nobel Prize 1997 to Stanley Prusiner for prion discovery.
Sporadic CJD (sCJD)
WHOThe most common form — approximately 85% of CJD. Cause: presumably spontaneous PrPC misfolding; no identified cause, infection or mutation. Typical onset: age 60-70; rapidly progressive dementia, myoclonus, cerebellar ataxia, visual disturbances; EEG may show periodic sharp wave complexes; MRI: cortical ribboning and basal ganglia hyperintensity on DWI; median survival 5-6 months.
Variant CJD (vCJD)
WHO/UKCaused by consumption of BSE-contaminated beef products. Younger onset (median 28 years) than sCJD; psychiatric symptoms first (depression, withdrawal); painful sensory symptoms; later dementia, myoclonus; longer disease course (14 months). MRI: pulvinar sign (posterior thalamic hyperintensity). Tonsil biopsy positive for PrPSc. 232 confirmed cases globally (predominantly UK).
Fatal familial insomnia (FFI)
WHOA rare genetic prion disease — caused by D178N mutation in PRNP gene + methionine at codon 129. Presents with progressive insomnia, autonomic dysfunction, and motor abnormalities. Death within 7-36 months. The sleep-wake cycle collapses completely — patients enter a state of perpetual wakeful stupor.
RT-QuIC (Real-time quaking-induced conversion)
WHO/ResearchAn ultrasensitive assay for CSF (and other samples) — amplifying minute quantities of misfolded PrPSc seeds by accelerated shaking. Achieves approximately 95% sensitivity and near-100% specificity for sporadic CJD. Revolutionised antemortem CJD diagnosis, replacing the need for brain biopsy. Now recommended by WHO for CJD diagnosis.
BSE (Bovine Spongiform Encephalopathy)
WHO/UKMad cow disease — a prion disease of cattle that emerged in the UK in the 1980s, linked to feeding cattle meat-and-bone meal from sheep with scrapie. UK BSE epidemic peak: approximately 37,000 cattle cases/year (1992). BSE was transmitted to humans through consuming infected cattle products, causing vCJD. Banned meat-and-bone meal feeding and selective culling controlled the BSE epidemic.

Latest GMJ coverage

Silent spread of chronic wasting disease raises cross-species transmission concerns
09/07/2026
How Protein Structure Determines Life and Disease: A Molecular Framework
03/08/2026

Frequently asked questions 12 Q&A — structured for Google featured snippets and AI discovery

Knowledge hub: guidelines, conventions and reports

Organizations working in migration and health

Related health topics

Dementia (rapid differential)Rare fatal neurological diseasesPatient safety (instrument decontamination)Blood safety (vCJD blood)Food safety (BSE-vCJD)Genetic neurological diseases

About this hub. Produced by the GMJ News Editorial Team as a public-good service. Every statistic is linked to its primary source. Documents are preserved in the GMJ Repository with full attribution. Georgian Medical Journal · Contact the editorial team
GMJ BriefsView all →
●What Healthcare Providers Need to Know About Sandwich Generation Caregivers2 hours ago●New Data: Unstable Connectivity Amplifies Loneliness More Than No Internet at All2 hours ago●Announcement: Magnesium deficiency linked to multiple chronic diseases: what clinicians need to know2 hours ago●Ultra-Processed Foods Account for Majority of Calories in Latin American Retail8 minutes ago●What Clinicians Must Know: Screening and Managing Immigration-Related Family Separation Trauma8 minutes ago●Announcement: Vitamin C May Reverse Skin Aging at the Genetic Level, New Research Suggests8 minutes ago●Three Clinical Advances in the UK's Updated Influenza Vaccine Framework2 hours ago●Announcement: Bones as Metabolic Organs: How Mechanical Loading Triggers Glucose Control2 hours ago●New Data: Combat Trauma in SOF Creates Cumulative, Multi-Domain Health Burden2 hours ago●Global Adolescent Obesity Climbing—Digital Marketing and Inequality Are Key Culprits4 hours ago