RNA - Picornaviridae

Question 1

Is picornviridae enveloped or nonenveloped?

Answer 1

nonenveloped

Question 2

How do picorn virions appear in electron micrographs?

Answer 2

smooth and circular

Question 3

What is the genome RNA protein of picorn? Is the genomic RNA infectious or noninfectious?

Answer 3

Genomic RNA has a protein, VPg, linked covalently to its 5’- end.

Genomic RNA is infectious.

Question 4

T/F:  Most picornaviruses cause rapid cell death with characteristic CPE (cytopathic effects)

Answer 4

True

Question 5

Picron consists of how many genera?

Answer 5

29

Question 6

What distinguishes the different genera of picorn?

Answer 6

their stability at low pH

Question 7

Etiology of FMD?

Answer 7

Alpthovirus

aptha means smal ulcer

Question 8

How many serotypes of FMD? Subtypes?

Answer 8

7, 80

Question 9

Which species is genetically resistant to FMD

Answer 9

Horses.

All hooved animals can get FMD

Question 10

Where is FMD still enzootic?

Answer 10

FMD is still enzootic in much of Africa, Asia and the Middle East.

Question 11

Stability of FMD - what is FMD is sensitive to?

Answer 11

virus is sensitive to acid and alkaline pH [stable at pH 6-9], sodium hydroxide, sodium carbonate and citric or acetic acid are effective disinfectants.

Question 12

How is FMD transmitted?

Answer 12

Inhaled/Aerosol. Can spread over countries

Question 13

Patho of FMD?

Answer 13

Inhalation/Ingestion  Oropharyngeal infection  Viremia  Spread to different organs & tissues  Replication in epidermal cells  Characteristic vesicular lesions.

Question 14

Which disease would you find the Tiger Heart and what species?

Answer 14

Commonly seen in fatal FMD cases in young calves, lambs, goats, pigs and buffaloes

Question 15

When is FMD detectable in Cattle and sheep?

Answer 15

 Cattle: up to 2 years  Sheep: up to 6 months

Question 16

Is FMD persistent in swine?

Answer 16

No woman!

Question 17

T/F:

FMD virus may persist in the pharynx of some animals for a prolonged period after recovery.

Answer 17

True

Question 18

T/F: FMD clinical signs: Most severe in pigs and intensively reared cattle

Answer 18

False. Vice versa

Question 19

Disease in Cattle?

• Fever, anorexia, depression, and a marked decrease in milk production.
• Drooling and vesicles appear on tongue and gums, interdigital skin, coronary band, teats.
• The vesicles soon rupture, producing large, crater-like ulcers

Answer 19

FMD

Question 20

Disease in Cattle?

• In calves up to 6 months of age = death.
• Tiger Heart
• Abortion
• Hairy Panters
  
  • Chronic syndrome of anemia, diabetes mellitus, overgrowth of hair and poor heat tolerance.
  • Probably due to Endocrine damage.

Answer 20

FMD

Question 21

What is the first sign of FMD in swine?

Answer 21

lameness is often the first sign

Question 22

Clinical signs of FMD in Sheep?

Answer 22

Mostly subclinical infections

If disease occurs, it is usually very mild

Question 23

How do you sample FMD?

Answer 23

Samples of vesicular epithelium or vesicular fluid should be sent in phosphate-buffered saline (pH 7.4) .

Samples must be kept as close as possible to pH 7.4 to prevent destruction of the FMD virus and antigen.

Question 24

What is the most preferred way to test FMD?

Answer 24

ELISA

Question 25

How do you distinguish infected animals from vaccinated animals (DIVA) with FMD.

Answer 25

Tests for antibodies to the nonstructural proteins (NSP) of FMD virus ## Footnote

Question 26

Is FMD reportable?

Answer 26

yes

Question 27

Is FMD zoonotic?

Answer 27

yes

Question 28

Etiology of Avian Encephalomyelitis?

Answer 28

Tremovirus

Question 29

What age is AE commonly found

Answer 29

1-3wk chicks

Question 30

Transmission of AE?

Answer 30

Fecal Oral. Via egg during viremia phase of laying the eggs

Question 31

What is the incubation of vertical transmission?

Answer 31

1-7 days

Question 32

What is the incubation of horizantal transmission?

Answer 32

11 days

Question 33

Are gross lesions seen in the infected brain of a bird with AE?

Answer 33

No woman!

Question 34

What is strongly suggestive of avian encephalomyelitis?

Answer 34

Central chromatolysis of neurons in the medulla oblongata

Question 35

T/F: Avian encephalomyelitis infection is seen as two distinct syndromes depending on the age when the susceptible chicken is infected

Answer 35

True

Question 36

Disease in chickens? * Ataxia and leg weakness that varies from sitting on hocks to paresis that progresses to paralysis and recumbency. * Fine tremors of the head and neck are evident in some birds and are characteristic of the disease (Epidemic tremors). * Prostration, blindness, coma and death.

Answer 36

Avian Encephalomyelitis

Question 37

What type of chickens would you find AE affecting the nervous system

Answer 37

Young chickens

Question 38

What type of chickens would you find AE showing no neurologic signs

Answer 38

Laying chickens side note: hatchability may drop due to lateembryonic mortality

Question 39

Birds that survive an acute infection of avian encephalomyelitis may develop what?

Answer 39

* cataract (a blue opacity of the lens). * CNS deficiencies.

Question 40

Describe the vaccine for avian encephalomyelitits

Answer 40

AE vaccine is usually combined with fowlpox vaccine and given by wing-web inoculation.

Question 41

T/F: AE virus causes disease in people or other mammals.

Answer 41

False

Question 42

Etiology of encephalomyocarditis

Answer 42

Cardiovirus

Question 43

What is the natural host of encephalomyocarditits?

Answer 43

Rodents

Question 44

In what species has fatality been reported in encephalomyocarditits?

Answer 44

swine and wildlife especially elephants

Question 45

How is encephalomyocarditits transmitted?

Answer 45

contaminated water or feed with rodent urine or feces transplacental

Question 46

T/F: Acute and subacute deaths are almost always attributed to the destructive effects of the virus on the myocardium.

Answer 46

True

Question 47

Disease in pigs? ## Footnote Nonsuppurative meningoencephalitis. Cases of reproductive failure due to near-term abortions (107–111 days of gestation), stillbirths, and mummifications

Answer 47

Encephalomyocarditis