Picornaviridae (FMD)

Question 1

What virus is highly resistant in the environment but variably sensitive to acid?

Answer 1

FMD

Question 2

FMD is enveloped or non-enveloped?

Answer 2

non-enveloped

Question 3

What shape does FMD have?

Answer 3

icosahedral

Question 4

FMD has a RNA or DNA genome and double or single stranded?

Answer 4

single stranded RNA genome

Question 5

True or false - FMD has many serotypes but immunity is not cross protective?

Answer 5

TRUE

Question 6

How many different serotypes does FMD have?

Answer 6

7

Question 7

how many subtypes does FMD have?

Answer 7

80

Question 8

FMD has cytoplasmic replication but ____ inclusion bodies

Answer 8

no

Question 9

how many hours does it take for the replication cycle to be completed in FMD?

Answer 9

5-10 hours

Question 10

Host cell protein synthesis is shut off within _____ in FMD?

Answer 10

30 minutes

Question 11

What pH is FMD unstable at?

Answer 11

unstable below 7

Question 12

FMD is enzootic in parts of?

Answer 12

Asia, Africa, and South America

Question 13

Up to ______ of virus is present in vesicular fluid in FMD

Answer 13

10^9 TCID(tissue cultured)/ml

Question 14

There are high virus titres in ____ secretions in FMD

Answer 14

respiratory

Question 15

Large volume of ____ & ______ of virus is shed from infected animals in FMD

Answer 15

droplets & aerosol

Question 16

True or False – FMD virus can become airbourne and spread up to 100-200 km

Answer 16

TRUE

Question 17

FMD has a _____ incubation period?

Answer 17

short

Question 18

True or false – FMD virus shedding happens during incubation or before clinical disease

Answer 18

TRUE

Question 19

in FMD, cattle act as _____ hosts

Answer 19

indicator

Question 20

in FMD, pigs act as _____ hosts

Answer 20

amplifier

Question 21

in FMD, sheep act as _____ hosts

Answer 21

maintenance

Question 22

Which species has severe disease manifestations?

Answer 22

cattle

Question 23

Which species has high virus output?

Answer 23

pigs

Question 24

which species has mild or subclinical disease?

Answer 24

sheep

Question 25

Where does a recovered animal carry the virus in the presence of FMD-antibody?

Answer 25

its pharynx

Question 26

True or false -- strong immunity to reinfection by the same but it des not last for life (~1 - 2 yrs)

Answer 26

TRUE

Question 27

True or false - many disinfectants are not effective against FMD?

Answer 27

TRUE --- sodium carbonate is most effective

Question 28

What disinfectants are resistant to FMD?

Answer 28

Resistant to iodophores, quaternary ammonium compounds, hypochlorite and phenol, especially in the presence of organic matter

Question 29

How do we prevent contact between susceptible animals and the virus

Answer 29

Household meat/bone scraps have to be boiled for 1 h before fed to pigs in NZ

Question 30

What 4 things can we do to stop further production of virus by infected animals

Answer 30

– Control (stop) animal movements – Tracing (at least 14 days before clinical signs) and surveillance – Eliminate possible sources of virus by slaughtering infected animals and known in-contact animals. Destroy carcasses properly. – Eliminate environmental contamination: decontaminate infected premises, vehicles, equipment, etc. Exterminate wild animals

Question 31

Is a FMD vaccine used in non-endemic regions?

Answer 31

NO

Question 32

Why wouldn't we use a vaccine in non-endemic regions?

Answer 32

– Masking of infected (shedding) animals – Vaccinated animals cannot be differentiated from infected serologically

Question 33

Is FMD an important and current virus in humans?

Answer 33

no very rare and unimportant

Question 34

What are clinical signs in humans if they do get FMD?

Answer 34

* Fever, anorexia * Vesiculation at the site of exposure (usually a skin abrasion) * Secondary vesiculation (mouth, hands, feet)

Question 35

What are the possible routes of infection for FMD to get into NZ?

Answer 35

Via imported live animals Via imported animal-derived products (meat, dairy, milk...etc) Via genetic material (embrios, semen) via travellers (clothing, shoes, goods) via imported farm equipment

Question 36

Clinical features of FMD in cattle:

Answer 36

– They get severe disease – Vesicles on the the tongue [dorsum], lips, gums, dental pad, cheeks and around the muzzle – Excessive salivation, smacking of the lips, anorexia – Vesicles or erosions also around the coronary band and in the interdigital cleft→lameness – Loss of hooves (exungulation) may follow laminitis – Vesicles and erosions on the skin of the teats→rapid drop in milk yield ± acute mastitis

Question 37

Clinical features of FMD in pigs:

Answer 37

– Also severe disease; lameness may be seen first – Vesicles commonly seen on, and especially around the edge of, the rostrum of the snout – Vesicles also on the feet [as in cattle] and around the supernumerary digits – Exungulation is common – In young pigs (and calves up to 6 months old) virus may localise in the heart and produce a severe myocarditis with sudden early death before vesicle formation

Question 38

Clinical features of FMD in sheep:

Answer 38

– Causes mild or subclinical disease – FMD is an important differential diagnosis for sudden-onset lameness in a flock