4. Olds (2nd exam)

Question 1

Major gross lesion on the internal organs of neonates or fetuses infected with herpesvirus.

Answer 1

Lungs = Interstitial pneumonia (aborted foal) ????

Question 2

Give 4 reasons on why ASFAR (African Swine Fever) is hard to control.

Answer 2

1. No treatment
2. No vaccine
3. Virus transmission via fresh meat and some cured meat products, can live for up to months or years in frozen meat.
4. Persistent infection in some pigs
5. Confusion with other disease like CSF, misdiagnosis
6. Persistent tick transmission

Question 3

Human adenovirus single-cell replication from attachment to release

Answer 3

illustration?

Question 4

Severe uveitis pathogenesis

Answer 4

1. Cav-1 enters eye – mild uveitis
2. CAV-1 specific antibody response increases in blood & reaches eye.
3. Complement fixation on virus-immune complexes free and in endothelial cells to chemostaxis of neutrophils –> leads to more severe uveitis & corneal endothelial injury.

Question 5

Give two reasons why puppies need multiple (2-4) shots of parvovirus vaccine.

Vaccination pupppies less than <16 weeks of age:
* 2 shots
* 2-4 weeks apart
* starting at 6-8 week old
* then at 1 year
* then every 1-3 years

Answer 5

1. Maternal antibodies inhibits vaccines, and only starts depleting at 16 weeks of age.
2. As maternal antibody decreases, parvovirus vaccine antibody needs to be sufficient until Mab is totally gone.

Question 6

Give two reasons why circovirus needs actively dividing cells.

Answer 6

1. Circoviruses do not have DdRp and DdDp
2. Actively dividing cells are abundant in cellular polymerases

Question 7

Give 4 reasons why parvovirus is difficult to control causing worldwide mortality in 1970s.

Answer 7

1. Virus stability - highly transmissible, not easily killed by ordinary disinfectants (should be 1:30 bleach solution)
2. Efficient feco-oral transmission
3. Susceptibility of animals
4. Parvovirus infections target actively dividing cells which are present in puppies
5. There is a high risk for the spread of infection through direct contact since puppies stay together
6. High viral shedding (10^7 particles per gram of feces)
7. Low amount of virus to infect (10 particles)

Question 8

Papilloma replication and production of warts.

Answer 8

1. Virus forces cell to continue dividing
2. Cell normally stops dividing (terminally differentiated)
3. Virus in latent form (episome) during normal keratinocyte divisions.
4. Infection of basal keratinocytes

ILLUSTRATION

Question 9

Structures of poxvirus and asfarvirus.

Answer 9

draw