Picornaviridae Flashcards
Picornaviridae: general
spherical, non-enveloped, smooth app.
Picornaviridae genome
single molecule, positive-sense ssRNA, infectious
Picornaviridae has a protein attached to 5’ end of RNA called
VPg protein
Picornaviridae replication takes place in
the cytoplasm
Picornaviriuses cause a characteristic ___ (action
cytopathic effect
rapid cell death
Picornaviriuses are stable at ___ pH
Low pH
Aphthovirus causes
Foot and mouth disease (FMD)
FMD effects all ___ animals. ___ (animal) is resistant
All cloven footed animals
Horses are resistant
FMD: transmission
Inhalation- main
direct contact, contaminated animal products, fomites, ingestion
FMD: pathogenesis
oropharyngeal infection- viremia- replication in epidermal cells- vesicular lesions
FMD can lead to myocardial lesions of focal necrosis called __
Tiger heart
High mortality is calves
FMD virus persistance does not occur in ___ (species)
Swine
In cattle up to 2 years
Sheep up to 6 months
FMD: CS in cattle
fever, anorexia, depression, decreased milk, hypersalivation, vesicles on tongue and coronary bands
may lead to crater-like uclers
Common sequel to FMD is
Hairy panters- chronic anemia, diabetes mellitus, excess hair growth, poor heat tolerance
due to endocrine damage
Often first sign of FMD in swine is
Lameness
less prominent ulcers in cattle, vesicles on snout
FMD: CS in sheep
often subclinical or mild disease
FMD: diagnosis
samples of vesicular epithelium or fluid
ELISA, virus isolation, PCR
DIVA of nonstructural proteins
T or F
FMD is reportable
True
FMD: Control
vaccine (only of that serotype), quarantine and slaughter in outbreak
FMD: CS in humans
often subclinical
fever, anorexia, vesiculation
Tremovirus causes
Avian encephalomyelitis
epidemic tremor
AE: infects
chickens: 1-3 wks of age
AE: transmission
fecal-oral
some vertical observed
AE: central chromatolysis is seen in __ (part of organ)
Medulla oblongata
AE: CS in chicks
CNS signs, ataxia, leg weakness, tremors of head and neck, paralysis, blindness, death
AE survivors may develop
Cataract- blue opacity of lens
AE: CS in layers
no CNS
drop in egg production and hatchability
AE: diagnosis
CS, virus isolation, immunofluorescent or histochem staining
AE: control
depopulation, vaccine
Cardiovirus causes
Encephalomyocarditis
Cardiovirus natural host are
rodents
infects many types of animals
Cardiovirus: transmission
ingestion of contaminated food/water
Transplacental
Cardiovirus: CS
acute death, due to destruction of myocardium
Weak heart, pulmonary edema, frothy transudate in resp. tract
non-suppurative meningoencephalitis
abortion, stillbirth, mummies
