37. Epidemiology and prevention of prion diseases

Prions
- = wrongly folded proteins which are very resistant, especially against heating
- The protein in question is called PrP and is normally in the C isoform (PrPC protein)
- Transformation to the Sc (scrapie) isoform can occur when a PrPC protein comes into contact with a PrPSc isoform of the protein
  - It can also occur spontaneously, but that is extremely rare
- The Sc isoform is resistant to proteolysis
- Transmissible per os
Prion diseases = transmissible spongiform encephalopathies (TSE)
- Bovine spongiform encephalopathy (BSE)
  - In 🐄
  - BSE epidemic occured in 80s – 90s Britain after feeding cattle with prion-contaminated meat and bone meal (MBM)
  - Can be transmitted to humans
- Scrapie
  - In sheep and 🐐
- Creutzfeldt-Jakob disease
  - In humans
  - Familal or spontaneous
- Variant Creutzfeldt-Jakob disease
  - In humans
  - Similar to Creutzfeldt-Jakob disease but caused by eating prion-contaminated beef (BSE)
- Kuru disease
  - In humans
  - Acquired through cannibalism
  - Nowadays extinct after the cannabalistic Fore people in Papua New Guinea stopped funerary cannibalism
- Fatal familial insomnia
  - In humans
Prevention
- In response to the british epidemic, import of british beef was banned worldwide (and still is many places today)
- Preventing BSE in cattle is the most important preventative measure
  - Health politics must ensure correct handling and feeding of cattle
  - Affected animals should be euthanized and destroyed
- Destruction of prions
  - Autoclaving
  - Proteases
  - Denaturating agents