Brainscape's Knowledge GenomeTM

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


See full index

Small Animal Final Year > Viruses and Lymphoid System > Flashcards

Viruses and Lymphoid System Flashcards

1
Q

Name a virus cause by Alpharetrovirus (2)

A

Avian leukosis virus

Rous sarcoma virus

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

What virus is caused by Betaretrovirus?

A

Jaagsiekte sheep retrovirus

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

Name a virus caused by Gammaretrovirus

A

Feline leukaemia virus

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

Name a virus caused by Deltaretrovirus

A

Bovine leukaemia virus

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

Name a virus caused by Epsionretorvirus

A

Fish tumour viruses

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

Name 3 viruses caused by Lentivirus (5)

A

Human immunodeficiency virus

Feline immunodeficiency virus

Equine infectious anaemia virus

Caprine arthritis-encephalitis virus

Maedi-visna virus

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

What is the prevalence of FeLV?

A
  • Variable
  • Much decreased due to vaccination and test/removal schemes

Strays!

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

What are the subtypes of FLV?

A
  • FeLV can cause immunosuppression, tumours, anaemia, enteritis.
  • Immunosuppression probably due to virus replication in cell progenitors in BM

–cytokine dysregulation? With how they mature and grow

•Different subtypes: A, B, C and T

–B, C and T less common

•Classified according to the viral envelope (gp70)

–Something about this

•FeLV B arises due to homologous recombination between A envelope and endogenous FeLV related DNA

–probably increases rate of tumour formation

•FeLV-C arises, rarely, de novo due to point mutations in the envelope

–causes severe rapid fatal aplastic anaemia

•FeLV-T targets T-lymphocytes

–causes severe immunosuppression

•FeLV-A isolated in all infected animals

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

How is FelV transmitted?

A

Virus is labile in the environment so close contact important for spread

Not stable for long in the environment once it dries out

Across placenta – tend to die in utero

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

Discuss FeLV disease

A
  • transmission by close contact (saliva)
  • occasional vertical transmission from infected queens (in utero or after birth via saliva or milk)
  • following infection most cats clear virus and recover – some become persistently infected (PI<30%)
  • PI cats will typically die within 3 - 4 years
  • Clinical signs include leukaemia, lymphoma, anaemia, immunosupression, enteritis
  • Young kittens more likely to become PI
  • Most cats tend to die 1-2 years
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the pathogenesis of FeLV?

A
  • Oronasal infection
  • Virus infects lymphocytes in oropharynx then spreads to local lymph nodes
  • Virus infects local lymph nodes, travels to bone marrow and other lymphoid tissues, then to mucosal tissues
  • Incubation period of 3-6 weeks until virus is found in the blood and is excreted in saliva
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When should we test for FeLV?

A

•Signalment

–Younger cat, possible exposure (stray?)

•“Appropriate” clinical signs

–Anaemia

–Neoplasia

•lymphomas, leukaemia

–Immunosuppression

  • co-infections e.g. stomatitis, respiratory, chronic illness
  • Management of populations

–Multi-cat household, shelters

–Cant always test - ££

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

How do you diagnose FeLV?

A

Aim to identify cats that are persistently viraemic

By definition have NO antibody to the virus

  • so need to detect VIRUS ANTIGEN (p27)
  • or circulating virus

In house screening test kits

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

What are the pros and con of in house FeLV testing?

A

–Negative results reliable (NPV >99%)

–Very unlikely it wont have the disease

–If there a clinical signs grumbling on you can then re test

–False positive results are possible (PPV 70-90%)

–Blood haemolysis

–Incorrect test use

–Antigen cross reaction

–Any positive result should be tested by virus isolation or immunofluorescence

–Recent infections should be retested in 12wk

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

What is the value of qPCR in FeLV?

A

–Detects provirus in circulating WBCs not viraemia

–Negative predictive value very high

–Does not always correlate with viraemia

–Viral loads need consideration

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

How can we control and manage FeLV?

A

Correct diagnosis of PI cats

Test and removal (isolation)

Symptomatic and supportive treatment

Impact on chemotherapy of cancers

Antiviral drugs?

Interferons, Other?

Vaccination of at-risk cats e.g. Eurifel FeLV

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

What should you do with a PI diagnosis?

A

–Retest in 12 weeks

–Retest in reputable laboratory

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

How can retroviruses establish persistent infections?

A

Lentiviruses typically infect adult hosts

Must evade host immune responses

  • (virus accessory genes e.g. decrease MHC expression)

Tend to persist via cycles of cell killing, virus release and re-infection

Cell destruction leads to disease

Infect macrophages/monocytes +/- lymphocytes

KEY POINT: Once infected there is effectively no chance of recovery

19
Q

What is the relatioship between Lentiviruses and immunodeficiency?

A
  • Infection of monocyte/macrophages and lymphocytes
  • Reduction of CD4+ T lymphocyte counts
  • Peak in 3 months then IR control
20
Q

What is the Immunopathogenesis of FIV?

A
  • Infection of CD4 T-helper lymphocytes.
  • Decreased CD4 cell count.
  • Marked lymphadenopathy.
  • Virus also targets CD8 T-cells, B cells, macrophages and glial cells.
  • Lymphoid tissues of intestines may also be affected.
  • Follicular destruction/dysplasia seen in later stages of disease.
21
Q

Discuss the stages of FIV

A
  • Acute transient illness several weeks after exposure.
  • Long asymptomatic carrier state.
  • Chronic disease characterised by secondary infections e.g. respiratory, oronasal, enteric, urinary.
  • Severe disease in terminal stages with cachexia, anaemia, diarrhoea, leukopenia, opportunistic infections e.g. Poxvirus, cryptococcus, candidiasis.
22
Q

What neoplasias are seen with FIV?

A

B cell lymphoma

Extranodal: gut, liver, spleen

Tumours are rare cf. FeLV

23
Q

Which cats are at risk of FIV?

A

Promiscuous (unneutered)

Old

Male

Stray (free-ranging)

Associated with biting

24
Q

How is FIV transmitted?

A

Horizontal

rarely transplacental

biting through umbilical cord?

kittens receive maternally derived antibody which persists until 16 weeks of age

25
Q

How do we diagnose FIV?

A
  • Diagnosis by detection of antiviral Ab
    • PPV of SNAP test ~95%, NPV 100%
    • Cats may be antibody negative up to 12wk post-infection
    • Young kittens born to FIV+ dams will have MDA – wait or test with PCR based test
26
Q

How do we control FIV?

A
  • Control of feral cat populations
  • Prevent transmission from FIV+ cats
    • reduce risk of fighting
    • no new cats in household
    • may occur in the absence of biting?
  • Vaccination?
    • Not available in UK.
27
Q

Why is there an obstacle with vaccinatiion for FIV?

A

Huge genetic variation

28
Q

What is suppressed with FIV?

A

CD4 lymphocytes

29
Q

Equine infectiouc anaemia virus:

A) How is it transmitted?

B) What happens if you find it?

C) How does the virus establish?

D) What is the diease related to?

A

A) Biting insect

B) Notify

C) Virus establishes persistent infection in face of vigorous host immune response

D) Immune complex formation

30
Q

What are the clinical signs of Equine Infectious Anaemia Virus in the acute phase?

A
  • Fever, diarrhoea, lethargy, restlessness, colic, rapid breathing, nasal and ocular discharge, emaciation, oedema, paralysis of hindquarters
  • Anaemia
  • High levels of circulating virus
31
Q

How do we diagnose equine infectious anaemia virus?

A

•Confirm horses negative by Coggins test (Agar Gel Immunodiffusion test detects antibody)

32
Q

Who is affected by Infectious bursal disease virus?

A

2-6 week old chicks

33
Q

What is theere tropism for with Infectious bursal disease virus?

A

Lymphocytes in bursa and thymus

34
Q

What are the clinical signs of Infectious bursal disease virus?

A
  • watery diarrhoea, cloacal inflammation
  • Immunodeficiency: opportunistic infections poor vaccine responses
35
Q

What is the difference here?

A

Left - normal bursa

Right - infectious burssal disease

36
Q

Label

A

A) Normal

B) Post infection

C) Cysts

37
Q

How can we control Infectious bursal disease?

A
  • Emergence of very virulent (VV) strains (>50% MR)
  • No treatment for disease
  • Difficult to eliminate
  • Attenuated or recombinant vaccines (variable efficacy)
  • Controlled by vaccination of breeding stock
38
Q

Aleutian disease of mink:

A) Which virus?

B) What happens?

C) What does it lead to?

D)) Whhat does it cause?

E) What happens in ferrets?

A

A) Parvovirus

B) Viral-Antibody complexes are formed but not eliminated

C) To immune complex disease

D) Chronic disease: Glomerulonephritis, splenomegaly, arteritis etc

E) scending paralysis

39
Q

What are the clinical findings of Malignant cattarhal fever?

A
  • Single animals
  • Depressed, anorexic, milk drop, wt. Loss
  • Nasal, ocular discharges
  • Corneal oedema
  • Marked pyrexia (>41°C), sweating
  • Oral, nasal ulceration
  • Lymphadenopathy
40
Q

How do you diagnose Malignant cattarhal fever?

A
  • Clinical signs can be highly suggestive
  • Confirmation by antiviral Ab detection or PCR
  • No effective treatment
41
Q

How do you manage Malignant cattarhal fever?

A
  • No vaccine
  • Avoid mixing of sheep/cattle around lambing time
  • Management systems in zoo collections
42
Q

What forms with Feline infectious peritonitis?

A

Immune complexes

43
Q

What is the effect of Bovine viral diarrhoea on the immune system?

A

–Immunosupression predisposes to respiratory disease complex in calves (BHV, RSV, Mannheimia etc) or calf diarrhoea

44
Q

What is the effect of parvovirus on the immune system?

A

Panleukopenia: decreased white blood cell count, killing of lymphoid and myeloid stem cells

Small Animal Final Year (317 decks)

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