Lecture 14: paramyxoviruses Flashcards
Where does canine distemper virus replicate
cytoplasm
is canine distemper virus segmented or non-segmented
non-segmented, no reassortment
what important proteins are encoded in canine distemper virus
H or H/N
what species are infected in canidae CDV
dogs
what species are infected in procyonidae CDV
racoons
what species are infected in felidae CDV
large cats
what species are infected in ursidae CDV
bears
what species are infected in mustillidae CDV
ferrets
Lions in Serengeti were infected with CDV what was the major sign shown
grand mal seizures
what is pathogenesis of paramyxoviruses
- Viral penetration of respiratory epithelium
- Early replication in epithelial macrophages
- Migration to draining LN
- 1 viremia- lymphatic replication- fever and lymphopenia (3-6d)
- 2 viremia disseminates virus from LN to various epithelial tissues- GI, UT, respiratory (8-10d)
- CNS penetration (1-3wks) post systemic signs
when are animals able to be tested via FA for CDV
first 7-10 days
what are animals with CDV positive with antibodies on serology
10-25 days
T of f: up to 75% of infections with CDV are subclinical
true
what are some clinical signs of CDV
- Upper respiratory- mucopurulent d/c, dry/productive cough
- Lower respiratory- CXR show interstitial lung pattern, alveolar with 2 bronchopneumonia
- CNS- seizures or UMN/GP signs
how does CDV affect fetus/neonates
depends on stage of infection but can result in abortion, stillbirth or weak pups
what are some signs in puppy’s who were infected with CDV
- Enamel hypoplasia
- Cardiomyopathy
- Classic CDV- increased likelihood of CNS disease
what is histo sign of CDV
cytoplasmic and intranuclear inclusion bodies (eosinophilic)
how is CDV transmitted
- Aerosol via bodily fluids (even subclinical animals)
- Fecal-oral
- Fomites
how can you dx CDV and what difference between tests
- Blood sear- cheap but low sensitivity
- FA- fast, cheap, good sensitivity
- RT-PCR- most sensitive, expensive
- CSF serology
how do you tx CDV
supportive care
what is prognosis for neurological signs from CDV
not typically reversible- euthanasia or anti-CNS edema doses of dexamethasone
what are some other notable paramyxoviruses
- Rinderpest, Peste des Petits ruminants
- Hendra/Nipah viruses
- Newcastle disease
All FAD
what viruses are included in bovine respiratory disease complex and which are paramyxoviruses
- BVDV
- IBR/BHV1
- Parainfluenza virus (paramyxovirus)
- Respiratory syncytial virus (paramyxovirus)
What facilitates transmission of bovine parainfluenza virus and respiratory syncytial viruses
environmental conditions, stress
what cells do bovine parainfluenza virus and respiratory syncytial virus target
ciliated epithelial cells
what is function of ciliated epithelium and what are consequences when lost
clear stuff out of URT, so damaged get secondary bacterial infections
what does this show
syncytial formation in type 2 pneumocytes
Characteristic of bovine respiratory syncytial virus
what are some signs of Newcastle disease virus
- Acute respiratory disease
- CNS signs
- Diarrhea
what are the 3 virulent groups of Newcastle disease and which are exotic
- Virulent- velogenic (exotic)
- Moderately virulent- mesogenic
- Low virulence- lentogenic
what are some important molecular attributes that differentiate orthomyxoviruses from paramyxoviruses
Orthomyxoviruses are segmented -ssRNA, receptor is HA, replicates in nucleus, and has inclusion bodies in nucleus
Paramyxoviruses is linear ssRNA, receptors are HA/N, replicates in cytoplasm and has cytoplasmic and nuclear inclusion bodies
how do differences between Orthomyxoviruses and paramyxovirus affect direct microscopic and viral evolution
effect localization of inclusion bodies and orthomyxoviruses can due rapid reassortment due to segmented ssRNA
