Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Infectious Agents II > Exam 2: Flaviviridae > Flashcards

Exam 2: Flaviviridae Flashcards

1
Q

What are the virion properties of Flaviviridae?

A 
Virions are spherical
Diameter 40-60 nm (medium sized)
Inner core possible icosshedral symmetry
Lipid envelope
Genome: single stranded, positive sense RNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 3 genera of flaviviridae?

A

Pestivirus (BVDV)
Flavivirus (yellow fever virus)
Hepacivirus (hepatitis C)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the species of pestiviruses with animal health significance?

A

Bovine viral diarrhea virus 1
BVDV 2
Classic swine fever virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 2 biotypes of virus with BVDV?

A

Cytopathic

Non-cytophatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which biotype induces persistent infection with BVDV?

A

Non-cytophatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which BVDV biotype is/are virulent in cattle?

A

Both cytopathic and non-cytopathic may be

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the transmission and persistence strategies of BVD?

A

Induction of persistently infected hosts that shed and transmit BVDV efficiently
Suppression of the host’s immune system
Transmission by various direct and indirect routes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the most important method of transmission for BVDV?

A

In utero infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the main determinant of fetal response in transplacental infections?

A

Timing of infection during pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe subclinical infections from BVDV in susceptible immunocompetent nonpregnant cattle

A

70 to 90% of infections in adult cattle
Mild fever and leukopenia
Development of neutralizing antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe BVDV infection in neonatal calves

A

Rarely seen in calves younger than 6 months

Severe enteritis, sometimes fatal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe venereal infections from BVDV

A

Semen in infected bulls contains virus
Semen quality may decrease
Seronegative cows inseminated with infective semen fail to conceive until they develop an immune response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is immunological tolerance?

A

State of unresponsiveness for a particular antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

When does immunological tolerance occur with BVDV?

A

When infection in utero between 80 and 125 days of pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe mucosal disease associated with BVDV

A

2 biotypes of BVDV are present
Persistent infection with non-cytopathogenic virus
Superinfection with a cytopathogenic virus
Clinical signs are similar to BVDV but more severe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the lesions with BVD?

A

Acute: erosive or ulcerative lesions in mouth, esophagus, forestomachs, abomasum and intestine
Discoloration of mucosal folds
Necrosis of lymphoid tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is used to diagnose BVDV?

A

RT-PCR
ELISA
Ear notches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the main route of classic swine fever infection?

A

Oronasasl by direct or indirect contact with infected pigs

Indirect by contaminated feed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does the severity of classic swine fever signs depend on?

A

Age of the animal and virulence of the virus

20
Q

Which form of classic swine fever is always fatal?

A

Chronic form

21
Q

What are the typical skin hemorrhages of classic swine fever?

A

Ears, tail, abdomen, and the inner side of the limbs

22
Q

Where does primary viral replication occur with classic swine fever?

A

Tonsils

23
Q

What does classic swine fever cause?

A

Severe leukopenia and immunosuppresion

24
Q

What is the major lesion caused by classic swine fever?

A

Infarction in the spleen

25
Q

Describe prenatal infections of classic swine fever

A

The piglets shed large amounts of virus

26
Q

What should be done classical swine fever is suspected?

A

It should be reported immediately

27
Q

Where should a sample come from when testing for classic swine fever?

A

Tonsils

28
Q

What can transmit Flavivirus?

A

Mosquito

Ticks

29
Q

What are viruses that fall in the Flavivirus genus?

A

West Nile Virus
Japanese encephalitis virus
Louping ill virus
Zika virus

30
Q

What is West Nile Virus serologically related to?

A

St. Louis encephalitis

31
Q

What are important reservoirs of West Nile Virus?

A

Passerines

32
Q

What are the prinicpal vectors of West Nile Virus in the USA?

A

Culex pipiens

C. restvans

33
Q

What are the 2 groups of birds infected with West Nile Virus?

A

Asymptomatic (carriers)

Susceptible (develop neurological disease)

34
Q

What does West Nile VIrus correlate with in terms of the North American bird population?

A

The decline in the population

35
Q

What is the range of avian West Nile Virus infections?

A

Subclinical to fatal with variability among species

36
Q

What are the signs associated with West Nile Virus?

A

Neurological

37
Q

In poultry, what has West Nile Virus been mostly reported in?

A

Ducks and geese

38
Q

What is another major animal that West Nile Virus has been reported in?

A

Horses

39
Q

What must you rule out in horses before you can confirm West Nile Virus?

A

Eastern Equine Encephalitis

40
Q

What is Japanese encephalitis a concern for?

A

Travelers

41
Q

What is Louping ill virus important in?

A

Sheep

42
Q

What ticks transmit Louping ill virus?

A

Ixodes ricinus

Rhipicephalus appendiculatus

43
Q

What are the signs associated with Louping ill virus?

A

Neurological

44
Q

What are the flaviviruses in humans?

A

Yellow fever
St. Louis encephalitis
Denge
Zika virus

45
Q

How is Zika virus transmitted?

A

Primarily though the bite of an infected Aedes species mosquito

Infectious Agents II (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions