Lecture 13: Reoviruses and rotaviruses Flashcards
Answer kahoot
Bovine papillomavirus
answer kahoot
double stranded DNA and single stranded RNA
What are the two types of reoviruses
orbiviruses and rotaviruses
what type of virus is epizootic hemorrhagic dz
reovirus, orbivirus
what are some signs of epizootic hemorrhagic disease
ulcers on tongue, petechiae hemorrhage along esophagus
t or f: epizootic hemorrhagic disease and bluetongue are reportable diseases
true
orbiviruses are __dsRNA
segmented
what is significance of segmented dsRNA
can take segments from multiple strains of virus in host and produce a completely new virus
what is the vector for orbiviruses
culicoides
what is the geographic distribution for orbiviruses
tropical and subtropical
how do reoviridae viruses replicate
- Attach to host receptors and endocytosis
- Partial uncoating in endolysozomes
- Early transcription of genome by viral pol within viral particle (still in cytoplasm) dsRNA—>mRNA
- MRNA segmented translation
- Viral protein/RNA aggregation and encapsulation
- Release of mature virions with cell death
what is the significance of reovirdae viruses doing partial uncoating during replication
hide from innate immune system because dsRNA not in healthy cells
where does transcription of reovirdae viruses like EHD take place
within viral particle in cytoplasm
how are EHD and BTC distinguished
subtle antigenic differences
t or F: African horse sickness is in united states
false
what bluetongue viruses are endemic to North America
BVT-2,10,11,13,17
what BTV are non-endemic to US and considered FAD
BTV-8, 4, 1, 14
t or f: EHD is endemic in North America
true
what is orbiviruses pathogenesis
- Exposure to vector
- Primary viremia—> bone marrow
- Secondary viremia—> endothelial cells
- Edema, hemorrhage, thrombosis, DIC
what are some clinical signs of orbiviruses (BTV, EHD)
- Fever >106.0
- Oronasal discharge, hypersalivation, oral necrosis
- Coronary band damage, lameness
- Sudden unexplained death (EHD)
Called out to sheep farm for sheep who suddenly died, presented with oronasal discharge, ulcers. What is your concern/dx
EHD/BTV
how do you dx orbiviruses
- Insect vectors present (culicoides)
- AGID
- ELISA
answer kahoot
mature enterocytes
what is pathogenesis of rotaviruses
- Feco-oral transmission
- GI passage—> enterocytes
- Loss of mature enterocytes at tips of villus
- Bacterial proliferation
- Malabsorptive and secretory diarrhea
what do rotaviruses target
tips of villi/mature enterocytes
what are some clinical signs of rotaviruses
Last 3-4d, non-bloody +/- watery diarrhea
how do you dx rotaviruses
Serogroup A ELISA/latex agglutination
how do you prevent rotaviruses
- Oral vaccine
- Clean environment
- Colostrum- maternal Ab’s
what is tx for rotaviruses
supportive fluids, management of concurrent infections
what type of virus is infectious bursal disease virus
birnavirus
what are some necropsy findings consistent with infectious bursal disease virus
- Ecchymotic hemorrhage in pectoral muscles
- Enlarged bursa fabricius, edema
from chicken- what concern/dx
Infectious bursal disease virus
where does brnaviridae (IBDV) dsRNA transcription occur
within virion
what is tx for infectious bursal disease virus
- Depop/repop/all in all out
- Vaccination
- Husbandry and biosecurity
what cells does IBDV target and what is result
B cells, causing immunosuppression
how do birnaviruses and other dsRNA viruses avoid detection by immune system
early replication occurs in vision to avoid exposing dsRNA
how is IBDV dx
ELISA +/- VI, RT-PCR +/- genome sequencing
answer kahoot
Within viral particle itself
