Reoviruses and Rotaviruses Flashcards
what orbiviruses are present in North America?
EHD
bluetounge
-endemic; exotic forms of EHD and bluetounge
EHD= epizootic hemorrhagic diarrhea
What orbiviruses are present outside of North America?
AHS
-different strains with potential higher virulence
AHS= african horse sickness
what clinical signs are associated with orbiviral infections in ungulates?
high fever
oral ulceration
pulmonary edema
lameness
sudden death death
what is the pathogenic process that is associated with the clinical symptoms of orbiviral infections in ungulates?
sudden death due to severe endothelial damage
what important differentials produce overlapping clinical signs?
EHD: BT
BT: EHD
vesicular diseases
MCF
adenovirus
how are orbiviruses transmitted? and when might you expect to see them seasonally?
Culicoides midges
cases typically peak in the fall months
what available diagnostics are at your disposal for detecting orbiviral infections?
AGID
RT-PCR
clinical signs and history
what is the vector for orbiviruses?
Culicoides spp (midge)
how is orbiviruses replicated in host????
segmented dsRNA
how is reoviridae replicated?
-attachment to host receptors and endocytosis
-partial uncoating in endolysozomes
-early transcription of the genome by viral pol within viral particle dsRNA->mRNA
-mRNA segmented translation
-viral protein/RNA aggregation and encapsidation
-release of mature virions with cell death
how are orbiviruses diagnosed?
insect vectors present?
AGID and ELISA
what are some important differentials for rotaviral infection in neonates?
parvo
corona
BVDV
parasitic infections
foreign body
how would you efficiently rule in/out the differentials for rotaviral infections?
species and history
diarrhea diagnostic panels
describe the pathology and clinical signs associated with rotaviral infection. How and why does this differ from other viral causes of diarrhea?
villus blunting
non-hemorrhagic diarrhea ~3 days
when do clinical signs manifest in rotaviruse infections?
3-4 days non bloody diarrhea
how do you diagnose rotaviruses?
ELISA/latex agglutination
how do you prevent rotaviruses?
oral vaccine
what is the treatment for rotavirus?
supportive fluids
what are the clinical signs associated with birnavirus infections in birds, and what are the underlying pathologic mechanism of disease?
-moderate to high mortality depending on strain
-enlarged b of F
-ecchymotic hemorrhages
-IBDV targets B cells
causing immunoupsression
double stranded RNA is highly immunostimulative; how do birnaviruses and other dsRNA viruses avoid detection by immune system when replicating?
some of the early replication steps take place within the virion to avoid exposing dsRNA
how is BVDV diagnosed in birds, and how are different strains typed?
ELISA +/- VI
RT-PCR +/- genome sequencing
what conventional methods may be used to contain +/- prevent IBDV in chicken flocks?
depot/repop
all-in/all-out
vaccination and proper husbandry/biosecurity
