Virology Exam 2 - Reoviridae & Birnaviridae

Question 1

what is the significance of segmented viruses and reassortment

Answer 1

allows for a newer, better progeny strain compared to the original

involves mRNA transcription that released into cytoplasm, viral factories to form new virions

Question 2

Reoviridae
SHAPE
ENVELOPED/NON-ENVELOPED
DNA/RNA
pathogens of ______

Answer 2

icosahedral/spherical (2-3 concentric layers)
non-enveloped
segmented dsRNA
arthropods and enteric

Question 3

Rotavirus
TRANSMISSION
DISEASE
SPECIES SPECIFIC GROUPS

Pathogenesis compared to Parvovirus

Answer 3

horizontal
rotavirus diarrhea, milk scours
A humans, cattle, other
B humans
C & E swine
D & F fowl

affects intestinal villi rather than crypts; enterotoxin NSP4

Question 4

what are the three Orbiviruses

what do they have a tropism for?

how are they all transmitted?

Answer 4

1. bluetongue virus (BTV)
2. Epizootic Hemorrhagic Disease Virus (EHDV)
3. African Horse Sickness Virus (AHSV)

endothelial & reticuloendothelial cells (macrophages/DC)

Culicoides biting midge

Question 5

Bluetongue Virus (BTV)
serotypes?
HOST
TRANSMISSION
DISEASE
PATHOGENESIS

Answer 5

30 serotypes
sheep, cow (domestic/wild ruminants)
Culicoides
edema, coronitis, lameness, recumbency, nasal discharge, high morbidity/low mortality, oral ulcers, blue tongue
replicates in LN then reticuloendothelial cells and endothelial cells

Question 6

Epizootic Hemorrhage Disease Virus (EHDV)
serotypes?
HOST
TRANSMISSION
DISEASE

Answer 6

10 serotypes
deer (carcasses in creek) DIC
Culicoides
salivation, oral ulcers, edema of conjunctiva/head/neck, lameness

Question 7

African Horse Sickness Virus (AHSV)
serotypes?
HOST
TRANSMISSION
DISEASE

Answer 7

9 serotypes
equine
Culicoides
Antemortem-frothy nasal discharge ,edema near eye
Postmortem - mortality, edema, cardiac focal hemorrhage, hydropericardium

Question 8

what is imporant about african horse sickness virus

Answer 8

reportable/notifiable
exotic to US

Question 9

Colorado Tick Fever Virus
HOST
TRANSMISSION
DISEASE

Answer 9

small rodents, elk, marmots, deer, humans
ticks, transstadially
fever, myalgia, headache, meningoencephalitis, hemorrhagic fever

Question 10

Birnaviridae
SHAPE
ENVELOPED/NON-ENVELOPED
DNA/RNA
pathogens of _______

Answer 10

icosahedral
non-enveloped
segments dsRNA (2 segments)
bird, fish, shellfish

Question 11

Infectious Bursal Disease Virus (IBDV)
serotypes?
HOST
TRANSMISSION
DISEASE

Answer 11

2 serotypes
avian species, chickens, turkeys, penguins
fecal-oral, highly contagious
Gumboro disease, acute diarrheal disease in young chicks, immunosuppression in poultry

Question 12

Infectious Pancreatic Necrosis Virus
HOST
DISEASE

Answer 12

Trout, salmon, rockfish, flounder, carp, oysters, plankton
subclinical infections - highly pathogenic, 90% mortality; chronic shedders