L26: Reoviridae (Romero) Flashcards Preview

Virology (Fall 2014) > L26: Reoviridae (Romero) > Flashcards

Flashcards in L26: Reoviridae (Romero) Deck (25)
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1
Q

Reoviridae general characteristics

A
  • dsRNA
  • comprise “REO” (Respiratory Enteric Organs) viruses
  • most complex of virology families
  • infect wide variety of hosts
  • most not assoc. with dz (exceptions: rotaviruses and orbiviruses**)
2
Q

2 genera of reoviridae that DO cause disease?**

A

Rotaviruses

Orbiviruses

3
Q

Orbivirus genus general chars.

A
  • genus of reoviridae
  • transmitted via arthropod vectors
  • seasonal dz
  • climate change may widen their geographical activity (esp. African horse sickness, Blue Tongue viru, and Peruvian horse sickness)**
4
Q

Bluetongue virus general chars.

A
  • an orbivirus
  • acute dz in sheep
  • effects cattle less severely
  • genome composed on 10 dsRNA segments
5
Q

CS/path. of Bluetongue virus**

A
  • vascular endothelial damage –> edema, necrosis esp. of tongue, nose, face, etc.
  • coronary bands –> lameness
  • nasal d/c
  • “sore muzzle” due to congestion of nasal cavity**
  • serotype BTV can cross placenta –> abortion
  • pericardial/pleural effusion
  • virulence vaires depending on serotype**
6
Q

where does most Bluetongue virus persist after viremia? **

A

platelets and RBCs (may remain infected long-term)

7
Q

Which serotype of bluetongue virus invaded Europe from Africa? Virulence?**

A

Serotype 8; highly virulent for many ungulates

8
Q

mortality of Bluetongue virus is highest in which species?

A

sheep

9
Q

morbidity of Bluetongue virus

A

~100% in sheep, cattle, goats, deer, antelopes

10
Q

Dx of Bluetongue virus

A
  • CS
  • Virus isolation
  • RT-PCR
  • Serology: ELISA, AGP, or Virus Neutralization**
11
Q

3 methods of serology for Bluetongue virus**

A

ELISA
AGP
Virus Neutralization

12
Q

Prevent/Control of Bluetongue Virus

A
  • Vaccine (inactivated or live-attenuated; live-attenuated can cause abortion in ewes or undergo reassortment in vectors)
  • can’t eliminate vectors
  • only introduce Ab-negative animals to BTV-free area
13
Q

Immunity to Bluetongue virus determined by:

A

virus neutralizing antibodies (serotype-specific)

14
Q

epizootic hemorrhagic disease virus in what genus of reoviridae?

A

orbivirus

15
Q

epizootic hemorrhagic disease virus general chars.

A
  • transmitted by Culicoides insects
  • infection in ruminants usually subclinical
  • dz seen after drought periods
  • not contagious
16
Q

CS of epizootic hemorrhagic disease virus

A
  • excessive salivation, foaming around nose and mouth
  • fever, extreme thirst, mouth ulcers
  • swelling of head, neck, tongue
  • deer usually found dead near water sources
17
Q

African Horse Sickness belongs to what genus of Reoviridae?

A

Orbivirus

18
Q

African Horse Sickness chars.

A
  • high mortality in horses

- not in Americas (yet)

19
Q

CS of PULMONARY form of African Horse Sickness

A
  • severe resp. distress, death
  • stands w/ forelegs apart, neck extended, nostrils dilated
  • profuse frothy nasal d/c
  • seen in susceptible horses infected with highly virulent strains
  • pleural effusion
20
Q

CS of CARDIAC form of African Horse Sickness

A
  • fever
  • edema in eyelids, lips, tongue, larynx, neck, chest
  • congestion and hemorrhage of conjunctiva
  • pericardial effusion, hemorrhage
  • death 4-8 days later
21
Q

CS of Horse sickness fever caused by African horse sickness

A

transient fever
lack of appetite
high RR
very LOW mortality rate

22
Q

Trans./Path. of African Horse Sickness

A
  • vector-borne by midges
  • seasonal
  • virus replicates in local lymph nodes
  • vascular injury –> inflammation, mac release
  • pulmonary edema when virulent virus involved
  • less virulent viruses –> gelatinous yellow fluid in subcutis
23
Q

Dx of African Horse Sickness

A
  • CS
  • virus isolation
  • virus neutralization
  • RT-PCR (test of choice)
24
Q

Immunity to African Horse Sickness

A
  • recovered horses immune for life against that serotype and have partial immunity to other serotypes
  • passive immunity via colostrum
  • vaccines available
25
Q

zoonotic potential of African Horse Sickness

A
  • NOT zoonotic in wild

- zoonotic potential in labs and while making vax –> encephalitis, chorioretinitis, DIC