Prion/Transmissible spongiform encephalopathies (TSEs) Diseases

Question 1

Answer 1

Question 2

What are prions? (5)

Answer 2

Question 3

What are prion diseases? (5)

Answer 3

• = Prionoses = chronic progressive fatal nervous system diseases
• Prions = proteins abnormally folded from alpha-helix to beta-pleated sheets (= bad isoform -> cascade effect)

Question 4

What diseases do prion diseases include? (5)

Answer 4

Question 5

What is classical scrapie? (2)

Answer 5

• Known to occur in sheep flocks for about 350 years ago & probably before
• Endemic worldwide, except in Australia & New Zealand, where it has been eradicated

Question 6

What is atypical scrapie (Nor-98)? (6)

Answer 6

• First identified in Norway in 1998 (hence Nor-98)
• Unique epidemiological, molecular & phenotypic characteristics

Question 7

What are the routes of transmission of prions (scrapie in particular)? (9)

Answer 7

Question 8

How do prions cause disease? (Pathogenesis) (3)

Answer 8

Question 9

What are the main clinical signs of scrapie? (Difference between classical and atypical) (3)

Answer 9

Question 10

Classical scrapie clinical signs (10)

Answer 10

Question 11

Atypical scrapie clinical signs (6)

Answer 11

Question 12

Where are the atypical scrapie lesions?

Answer 12

Cerebellum

Question 13

Compare and contrast atypical and classic scrapie (6)

Answer 13

Question 14

What is BSE (Mad cow disease)? (4)

Answer 14

Question 15

BSE epidemiology (5)

Answer 15

Question 16

What are the main clinical signs of BSE? (3)

Answer 16

Question 17

What problems has BSE caused?

Answer 17

Question 18

BSE - non-specific clinical signs (4)

Answer 18

Question 19

BSE - pathology

Answer 19

Question 20

What is atypical BSE? (2)

Answer 20

Question 21

What are the three forms of BSE in cattle? (3)

Answer 21

Question 22

What do the immunolabelling patterns between the H-, L- and C-types involve? (3)

Answer 22

• L-type BSE shows immunolabelling within the molecular and granular layers of the cerebellum, like atypical scrapie in sheep.
• By comparison, the most striking feature in H-type BSE cases is widespread labelling throughout the WM of the cerebellum.
• C-type BSE shows increased vacuolation and immunolabelling within the more rostral brain, particularly the frontal cortex.

Question 23

TSE - gross and microscopic pathology (lesions) (7)

Answer 23

There are no pathognomonic gross lesions in TSE-infected animals.

Histo lesions:

Spongiform change in the grey matter neuropil

Astrocytosis

Neuronal vacuolation

Inflammation is absent.

Amyloid plaques are sparse or absent in the classic TSE.

Question 24

What are the additional diagnostic tests for BSE? (3)

Answer 24

Question 25

BSE - prevention and control (12)

Answer 25

Question 26

BSE - cattle surveillance - regulations

Answer 26

Question 27

Control measures when BSE identified (5)

Answer 27

Question 28

Scrapie - genotype control program (6)

Answer 28

Question 29

What is CWD? (4)

Answer 29

Question 30

CWD - clinical signs (10)

Answer 30

Question 31

What is TME? (2)

Answer 31

Question 32

What is FSE? (4)

Answer 32

Feline spongiform encephalopathy