Chapter 5 - Viruses

Question 1

virion

Answer 1

a mature virus. the infective form of a virus.

Question 2

what does it mean to be enveloped?

Answer 2

coated with host cell membrane components

Question 3

ubiquitous

Answer 3

present, appearing, found everywhere

Question 4

what is an interferon?

Answer 4

proteins made and released by host cells in response to the presence of pathogens such as viruses

Question 5

describe viruses (5 points)

Answer 5

• immunosuppressive
• genetically unstable entities
• sensitive to interferon
• chemotherapeutants difficult
• maintain virulence if passed through animals

Question 6

virulence

Answer 6

the relative ability f a microorganism to cause disease

Question 7

what is the difference between in vivo and in vitro?

Answer 7

vivo: studies conducted on living organisms in their normal intact state
vitro: studies conducted using components of an organism that have been isolated from their usual biological surroundings (test-tube experiments)

Question 8

the 4 fates of viral invasions inside cell:

Answer 8

• Lytic (acute)
• Persistant (chronic)
• Latent
• Abortive

Question 9

what does LYTIC mean, when referred to fate of viral invasions inside cell?

Answer 9

many viral progeny in a short period, host cell dies

Question 10

what does PERSISTANT mean when referred to fate of viral invasions inside cell?

Answer 10

few too many viral progeny over long time, host cell survives, but damaged

Question 11

what does LATENT mean when referred to fate of viral invasions inside cell?

Answer 11

no viral progeny, but can become productive later

Question 12

what does ABORTIVE mean when referred to fate of viral invasions inside cell?

Answer 12

genome enters cell, but no viral progeny produced (cell is RESISTANT)

Question 13

name three types of viral reproduction

Answer 13

• general
• lytic (non-enveloped)
• budding (enveloped)

Question 14

what are the five stages of diagnosis?

Answer 14

• observation: behaviour, external lesions, pathology
• microscopy: EM
• live cell culture: CPE (CHSE, SHK, RTG, FHM, SSN-1, EPC)
• serological tests: (ELISA, IFAT, FAT)
• genetic: (PCR, RT-PCR)

Question 15

Chemotherapeutics: what kind?

Answer 15

none.

only disinfectants:

• virkon
• peroxiguard
• Water sterilization (UV or Ozone)

Question 16

what is a NEW sort of prevention Vaccine?

Answer 16

Subviral preperations, DNA

Question 17

CFIA and NAAHP dictated that diseases get categorized three ways:

Answer 17

• reportable (most serious) must report immediately
• immediately notifiable (only applies to labs)
• annually notifiable (labs)

Question 18

where would one find IHN? (globally)

Answer 18

IHN is a local (endemic) virus