Feline retroviruses intro and Feline Immunodeficiency Virus (FIV)

Question 1

Give 3 examples of feline retroviruses

Answer 1

Feline leukaemia virus (FeLV)
Feline immunodeficiency virus
Feline syncytium-forming virus (FeSV)

Question 2

What is virus classification based on?

Answer 2

Genome (RNA/DNA)
Morphology
Number and sense of nucleic acids
Ecology
Similarity of genome

Question 3

Are retroviridae single stranded or double stranded? Are they DNA or RNA?

Answer 3

Single stranded

RNA

Question 4

Retroviridae are the only viruses that have which 3 features?

Answer 4

Truly diploid
Have genome produced by transcriptional machinery
Have a positive sense genome

Question 5

What is reverse transcriptase (RT)? What does it do?

Answer 5

Polymerase enzyme

Uses viral RNA genome as a template to copy RNA

Question 6

What is integrate (IN)?

Answer 6

Enzyme that binds viral DNA and inserts viral genome into host DNA

Question 7

What type of virus is feline immunodeficiency virus?

Answer 7

Lentivirus (related to HIV)

Question 8

Is FIV zoonotic? What does it cause?

Answer 8

No

Lesions, immunodeficiency

Question 9

In what cats is FIV more common?

Answer 9

Males

Over 5

Question 10

How is FIV transmitted?

Answer 10

Virus in saliva passed through biting

Also through placenta and milk transmission

Question 11

What is the pathogenesis of FIV?

Answer 11

Infects lymphocytes, macrophages, Kupfer cells and astrocytes
Gradually decreases CD4 and MHC II

Question 12

FIV causes viraemia after what period of inoculation?

Answer 12

7 days

Question 13

Where can the FIV virus be isolated from?

Answer 13

Blood
CSF
Saliva
Lymphoid organs

Question 14

What are the symptoms of FIV?

Answer 14

Initially appear healthy for 5 years to life

Fever, inflammation of LNs, general feeling unwell (malaise), acute enteritis, opportunistic infections

Question 15

What is the treatment for FIV?

Answer 15

Mainly supportive

Use reverse transcriptase inhibitor (unsure of long term effects, and resistance)

Question 16

How can FIV be prevented and controlled?

Answer 16

Prevent cats fighting

Isolate infected

Question 17

Is there a vaccination for FIV?

Answer 17

Yes but not in Europe

Question 18

What is an issue with FIV testing in kittens?

Answer 18

Queen passes maternal antibodies to kittens

All kittens will test positive, even if not infected (test regularly)

Question 19

How is FIV diagnosed?

Answer 19

Presence of FIV antibody

Question 20

Why is virus isolation not used for diagnosing FIV?

Answer 20

Slow
Expensive
Virus levels fluctuate during early infection

Question 21

Why do FIV antibodies prove infection (except in kittens)?

Answer 21

No vaccine to interfere with test

Cats can’t clear infection so Ab levels remain high for most of infection.