TSE

Question 1

List examples of TSE

Answer 1

Sheep & goats: scrapie, atypical scrapie

Mink: mink spongiform encephalopathy

Deer & elk: chronic wasting disease

Cattle: bovine spongiform encephalopathy

Cat: feline spongiform encephalopathy

Question 2

What are prions

Answer 2

Misfolded proteins

Self catalytic conversion – causes accumulation

Highly stable
Resistant to proteases
Resistant to heat treatment
Resistant to UV

Question 3

How are TSEs diagnosed

Answer 3

Transfer of brain extract to permissive experimental animal
Ethical issues
Long incubation before diagnosis

Specific identification of PrPSc (disease specific protein)
Histology
Immunohistochemistry
Spongy holes = TSE

Question 4

What are the clinical signs of TSEs

Answer 4

Weight loss

Behavioural changes

Licking lips, grinding teeth, scratching

Posture, gait

Ataxia, tremor

None, animal dead

Question 5

Discuss transmission of TSE

Answer 5

Difficult to transmit
All human TSEs
BSE (zoonotic)
MSE
Transmitted through medical procedures or ingestion of contaminated food

Readily transmitted
Scrapie in sheep
CWD in cervids
Transmitted through direct contact & environmental reservoirs

Question 6

Discuss BSE epidemic

Answer 6

Incubation period was years

Cohort culling if any animal had it

Feed ban for ruminant material

Older cattle banned from human food chain

Ban of specific risk material from food chain

Export ban

Surveillance