Feline Immune Deficiency Virus Flashcards
FIV Incidence
- Average 4% incidence in feral cats
- Average 1% incidence in domestic cats
- Sexually intact males incidence is higher:
○ Increased risk for fighting behaviour
○ Increased bite-wound transmission
What is FIV
T lymphotropic retrovirus
How does a virus work?
- Pathogen enters host cell via receptor on cell membrane
- Viral genes/enzymes are released into host cell
- Host cells internally replicate viral RNA by reverse transcriptase
- Viral DNA enters host nucleus and becomes incorporated in host cells using host cell machinery
- Assembly of viral components in nucleus via transcription
- Viral particulates undergo translation to become viral particles
- Viral particles exit host cell via exocytosis and infect new host cells
Specifics of FIV Infection
- Pathogen directly affects and replicates in CD4+ T cells
- Progressive decline of CD4+ T cells in blood and virus causes cytopathic effect on these cells
- Prefers CD4+ over CD8+ because of particular protein on cells
○ Primary binding receptor is called CD134
What clinical signs does a cat show in acute phase?
Acute signs of illness
Progressive immunodeficiency
○ Reduction of CD4+ T lymphocytes
○ Mutations within FIV virus limit reliance on CD134 receptor which would be a target for humoral response
Terminal Stage
○ Advanced immunosenescence
○ Chronic multisystemic disease
○ Inversion of CD4 : CD8 ratio and eventual loss of CD8+ lymphocytes in late stages of infection
Advanced immunosenescence
Process of immune dysfunction that includes remodelling of lymphoid organs leading to changes in immune function
Clinical signs
No typical clinical signs
May present with persisting infections which they should be able to fight off
May have several concurrent problems
Treatment
No effective treatment
Supportive care of secondary signs
Vaccination
No licensed in UK
