Feline immunodeficiency virus infection

FELINE IMMUNODEFICIENCY VIRUS INFECTION

  • Feline immunodeficiency virus (FIV) is a lentiviurs.
  • It was firs isolated in 1987 from domestic cats (in the United States) having an immunodeficiency syndrome.
  • The virus has since been identified in cats throughout the worlds.
  • FIV bears many similarities to HIV.
  • It is tropic for T lymphocytes, macrophages and astrocytes.

Transmission

  • The virus is shed mainly in the saliva, and it is transmitted primarily through bites.
  • Accordingly, the highest incidence is in the free-roaming (wild and per) male and aged cats (i.e., in cats living outdoors).
  • Very often FIV-infected cats are also infected with feline leukaemia virus (FeLV).
  • However, cats are ,pre adapted to FIV than are human to HIV and that FIV is less immunosuppressive than HIV.

Clinical signs

  • Following infection, there is a low-grade fever, generalized lymphadenopathy and sometimes, diarrhoea.
  • This is mostly seen in young cats, and usually persists for 2-4 weeks although lymphadenopathy may persist for several months.
  • This is followed by clinically normal interval of 1-2 years during which there is depression of the CD4+ to CD8+ T cell ratio.
  • Afterwards, infected cats may develop recurrent fever, lymphadenopathy, anaemia, diarrhea, and weight loss.
  • Chronic secondary infections, especially gingivitis, dermatitis and upper respiratory disease and opportunistic infections may occur at the final stages of disease.
  • Opportunistic infections include toxoplasmosis, calivcivirus infection, feline herpesvirus infection, candidiasis, cryptococcsis, haemobartonellosis, mycobacteriosis and others.
  • Several neurological abnormalities, including dementia, twitching, tremors and convulsions may also occur.

Gross and microscopic lesions

  • Lesions basically reflect those of opportunistic infectons.
  • Encephalitis, characterized by perivascular mononuclear infiltrations and glial nodules, is most likely a primary FIV lesion, comparable to the encephalitis seen in AIDS.
  • Care must be taken to rule out toxoplasmosis, or other agents that can lead to encephalitis.
  • Microscopically the lymphadenopathy is characterized by early follicular hyperplasia which may later progress to marked lymphoid depletion.
  • Cats remain infected for life.
  • The presence of serum antibodies is directly correlated with the ability to isolate virus from blood cells and saliva.
Last modified: Friday, 23 March 2012, 9:48 AM