Prions Flashcards
What is BSE called when it is transmitted to humans
Creutzfeldt-Jakob Disease (CJD)
When was the practice of feeding agricultural waste to animals banned
1988
Prion definition
Infectious agents made of protein material that can fold multiple abstract ways and at least one of which is transmissible to other prion proteins
Prions composed of what protein are the cause of TSE
Prion protein PrP
How do prions cause disease
Converting PrPC into aggregation-prone PrPSc
Strain
A defined prion population isolated from one specific animal
Type
Refers to a combo of biochemical parameters (size of unglycosylated PrPSc fragment after proteinase K partial digestion) that are independent from the host
Common characteristics of TSE disease
Long incubation periods, illness of weeks to months, PrPTSE accumulation in brain and other tissues, pathological changes confined to CNS, absence of immune response
Scrapie affects…
Sheep and goats
Chronic wasting disease affects…
Cervids
Transmissible mink encephalopathy affects…
Mink
Kuru affects…
Humans (historical)
Different strains of TSE cause what conditions
Scrapie, chronic wasting disease, TME, kuru
What is the incubation period of CWD
2-4 years
Where can PrPSc be found in CWD
Extraneural tissues, body fluids, and excreta (horizontal transmission is possible, one of the most contagious)
What is unique about CWD transmission
Indirect transmission occurs via CWD prion deposition into environment from urine, feces and saliva
How is BSE thought to arise in cattle
Genetic mutation
What is needed to inactive the BSE protein
Immersion in 1N NaOH or a dry heat at 1000C (very stable protein)
Symptoms of BSE
Degeneration of nervous system, changes in temperament, abnormalities in posture, nervousness and aggression, incoordination, tremors, hard to stand
What is the incubation of BSE
2-8 years
How long do clinical symptoms of BSE last
2 weeks to 6 months
Who was most afflicted by variant CJD
Adolescents (occasional cases in adults over 50)
What is the clinical presentation/duration of vCJD
Psychiatric disturbance and complaints of sensory symptoms like limb pain
Duration 14 months
3 regulations to control BSE
- Feed bans
- Specified risk materials bans (removed brain and spinal cord and destroy)
- Regulation of rendering (autoclave slaughter materials)
