Orthomyxoviridae

Question 1

What viruses are included in Influenza A?

Answer 1

human, equine, swine and domestic poultry viruses

Question 2

What viruses are included in Influenza B?

Answer 2

human viruses

Question 3

What viruses are included in Influenxa C?

Answer 3

human and swine viruses that rarely cause dz

Question 4

What is the only member of genus Isavirus?

Answer 4

infectious salmon anemia virus

Question 5

Tick borne viruses are in which genus?

Answer 5

Thogotovirus

Question 6

How are orthomyxoviruses classified?

Answer 6

based on type of HA and N

Question 7

How are influenza viruses named?

Answer 7

type/host/geographical origin/strain #/year of isolation/HN

e.g. A/equine/Miami/1/1963 (H3N8)

Question 8

T/F virions are pleomorphic and non-segmented

Answer 8

F: they are segmented

Question 9

T/F influenza F lack Neuraminidase

Answer 9

T

Question 10

3 functions of HA

Answer 10

receptor binding, membrane fusion, receptor cleavage

Question 11

genome composed of:

Answer 11

6-8 segments of linear, negative sense ssRNA

Question 12

Where does uncoating occur?

Answer 12

cytoplasm

Question 13

Where does viral protein synthesis occur?

Answer 13

cytoplasm using cell machinery

Question 14

How is the virus transmitted in aquatic birds

Answer 14

shed in feces -> fecal oral

Question 15

How is the virus transmitted in poultry?

Answer 15

ingestion and inhalation

Question 16

How if the virus transmitted in mammals?

Answer 16

aerosol, dropelets and fomites

Question 17

T/F genetic drift and shift occur in orthomyxoviruses?

Answer 17

T

Question 18

Where does equine influenza replicate?

Answer 18

epithelial cells of upper and lower respiratory tracts

Question 19

symptoms of equine influenza

Answer 19

fever, nasal discharge, dry cough, mucopurulent discharge in late stages

Question 20

T/F animals are no longer infectious when clinical signs disappear

Answer 20

F: remain infectious at least 5 days

Question 21

What type of horses are susceptible to equine influenza?

Answer 21

race horses, breeding stock, show jumpers

Question 22

T/F pigs can become co-infected with both avian and human strains of influenza

Answer 22

T: have human (SAa2,6Gal) and avian (SAa2,3gal) receptors

Question 23

Where does swine influenza replicate?

Answer 23

upper respiratory tract

Question 24

Is incubation of swine influenza long or short?

Answer 24

short

Question 25

T/F swine influenza is always fatal

Answer 25

F: not if animals are kept warm and stress free

Question 26

Are there vaccines for swine influenza?

Answer 26

Yes but don’t confer cross protection against new subtypes