Lecture 14

Question 1

Symptoms of Wellfleet Bay Virus (WFBV) (3)

Answer 1

1. Diarrhoea 2. Lethargy 3. Recumbency

Question 2

Clinical signs of WFBV

Answer 2

Lesions on liver

Question 3

What is WFBV closely related to

Answer 3

Quaranjavirus genus

Question 4

What type of animal does WFBV infect

Answer 4

Birds (common eiders)

Question 5

How big are Orthomyxoviruses

Answer 5

80-120nm

Question 6

What does Cygnet River virus infect

Answer 6

Ducks

Question 7

How did the ducks get Cygnet River virus

Answer 7

They were fed incorrecly

Question 8

What are natural host for influenza A

Answer 8

Wild waterbirds

Question 9

What are the subtypes of influenza A (2)

Answer 9

1. Hemaggutinin (HA) 2. Neuraminidase (NA)

Question 10

Where does avian flu virus usually replicate

Answer 10

Epithelial cells of GIT

Question 11

Where do birds excrete the virus in large quantities

Answer 11

Droppings

Question 12

How is avian influenza infection caught

Answer 12

Asymptomatically

Question 13

In influenza A, which subtypes have caused an endemic (4)

Answer 13

1. H1N1 2. H2N1 3. H2N2 4. H3N2

Question 14

Explain the subtypes and the species they infect

Answer 14

Question 15

What occurs in reassortment (ANTIGENIC SHIFT)

Answer 15

Occurs when 2 distinct influenza viruses concurrently infect the same person or animal and may result in progeny virus with genetic material from both viruses

Question 16

What occurs in mutations/adaptations (ANTIGENIC DRIFT)

Answer 16

Occurs when an influenza virus accumulates mutations that enable more efficient infection and spread in a new host

Question 17

What does viral replication use cells to do? (3)

Answer 17

1. Read own RNA 2. Synthesise proteins 3. Assemble the new viruses

Question 18

Where does RNA synthesis occur

Answer 18

The cells nucleus

Question 19

Where does protein synthesis occur

Answer 19

Ribosomes in cytoplasm

Question 20

During viral replication where does Hemagglutinin attach

Answer 20

Sialic acid receptors on the cell

Question 21

Where does influenza HA bind

Answer 21

to sialylated glycans on cell surface

Question 22

What are the clinical signs of LPAI (3)

Answer 22

1. Respiratory and/or GIT infection 2. Sneezing, coughing, ocular and nasal discharge, and swollen infraorbital sinuse 3. morbidity and mortality low

Question 23

What are the clinical signs of HPAI (5)

Answer 23

1. Severe, systemic disease 2. Cyanosis and edema of the head, comb and wattle 3. Oedema and red discolouration of the shanks and feet due to subcutaneous haemorrhages 4. Blood-tinged oral and nasal discharge 5. Greenish diarrhoea

Question 24

What are the 3 types AIV and NDV

Answer 24

1. Velogenic strains: high mortality 2. Mesogenic strains: respiratory disease in young chickens and decrease egg production 3. Lentogenic strains: mild respiratory infection or no symptoms

Question 25

Explain the evolution of influenza A/H5N1 virus

Answer 25

Question 26

What are some problems with A/H5N1

Answer 26

1. Large death in birds 2. Many birds have to be killed 3. Huge financial cost

Question 27

Where did the H7N9 virus occur

Answer 27

China

Question 28

What type of population does H7N9 effect

Answer 28

older males

Question 29

What are some strategies in markets to reduce avian viruses (3)

Answer 29

1. Market cleaning 2. Destocking overnight 3. Rest days

Question 30

Clinical signs of swine influenza (6)

Answer 30

1. Going off feed 2. High fever 3. Discharge from eyes and nose, sneezing 4. Breathing difficulties 5. Barking cough 6. Huddling and inactivity

Question 31

Why can pigs get infected with both human and avian viruses

Answer 31

Their tracheal epithelium has both receptors for avian and human viruses

Question 32

Which type of influenza virus in horses is the only one that still exists

Answer 32

H3N2

Question 33

Clinical signs of equine influenza (3)

Answer 33

1. Increase in temperature 2. Deep, dry, hacking cough 3. Watery nasal discharge which may later become thick and smelly

Question 34

Which 2 strains of influenza virus have been identified in dogs

Answer 34

1. H3N8 2. H3N2

Question 35

What two swabs are essential when swabbing a bird for influenza

Answer 35

1. Oropharyngeal swab 2. Cloacal swabs