Prions

When was scrapie first recorded in sheep?

1732

Who reported the first case of scrapie in a cow?

A French vet

When did rendering begin on a widespread scale?

1920s

What disease was first reported in 1920-1921?

Classical Creutzfeldt-Jakob Disease (CJD)

In what year was Kuru found in New Guinea cannibals?

1957

What were the first signs of BSE observed in February 1985?

Head tremors, weight loss, lack of coordination

When was BSE officially recognized as a disease?

1986

What was the peak number of confirmed BSE cases?

100,000

What was the connection between CJD and dairy farmers from 1993-1995?

Four cases of CJD reported in farmers

Who was the first known victim of variant CJD?

Stephen Churchill

What significant evidence was found in September 1997 regarding vCJD?

Link between vCJD and BSE in mice

What happened in February 2000 concerning vCJD?

A baby girl contracted vCJD

What are the main diseases caused by prions in humans and animals?

• Scrapie in sheep

• BSE in cattle

• Chronic wasting disease in elk

• Kuru in humans

• Creutzfeldt-Jakob disease in humans

What are the characteristics of prion diseases?

• Caused by small, proteinaceous particles

• Pathology includes large vacuoles in CNS

• Slow progression: 1-35 years from infection to symptoms

What is the molecular weight range of PrP?

~30 – 35 kDa

What is the difference between PrPc and PrPsc?

PrPc is uninfective; PrPsc is infective

How does PrPSc accumulate in cells?

• PrPc is released from the cell membrane

• Converted into PrPSc

• PrPSc accumulates as plaques

• Internalized by cells

What are the transmission routes for prion diseases?

• Contaminated food

• Contaminated medical products

• Blood and transplants

• Contaminated surgical instruments

• Shedding through skin, feces, urine, milk, saliva

Why is diagnosing prion diseases difficult?

No culturing or serology available

What are the characteristics of prion agents?

• Unusual infectious agents

• Host-derived glycoproteins

• Lack nucleic acid genome

• Resistant to disinfection procedures

What is the primary method of transmission for prion diseases?

Ingestion

What does iatrogenic transmission refer to in prion diseases?

Transmission via medical procedures