History and Prevalence

 Funny Cat

It is believed that FIV has infected the domestic feline population since 1966 (6) but the virus itself was not isolated until 1987 in California (10). 


FIV has worldwide distribution.  Prevalence varies by region and lifestyle of the cat.  Aggressive, intact males that spend a lot of time outdoors are most at risk for acquiring FIV (11).  Adult cats are more likely to present infection than are adolescent cats or kittens (6).  Globally, seroprevelence can range from 1% to 30%.  In the United States 1.5 to 3 % of healthy cats carry FIV and up to 15% of sick cats will have the disease (1).   The average age of infected cats is between 3 to 5 years old (10)


FIV is also found in non-domestic felids including lions, cougars, Pallas’ cat and bobcats.  Antibodies to FIV have been recognized in over eighteen different feline species (10).  It is believed that FIV has been around in non-domestic felids longer than domestic felids due to greater diversity of the viral nucleic acid  sequence and decreased pathogenicity of the viruses isolated in these wild animals (6)


No public health risks have been identified with FIV infections in humans (10).  Even after accidental exposure to the virus, no antibody to FIV was found in human serum.  However, cats with FIV resulting in immunodeficiency may be more likely to spread other zoonotic agents into the human environment (11)