The epidemiology of the feline leukemia virus (FeLV).

Clustering of cases of feline lymphosarcoma (LSA) has been observed by veterinarians for many years. In 1964 it was discovered that feline LSA was caused by an oncornavirus, the feline leukemia virus (FeLV). In 1970, a simple, indirect immunoflourescent antibody (IFA) test for FeLV was developed which enabled large numbers of cats, living in their natural (household) environments, to be tested for the virus. In one study, over 2,000 cats were tested and the results showed conclusively that FeLV is a contagious agent for cats. This finding was independently confirmed by several other investigators using different testing procedures. After discovering the contagious nature of FeLV a test and removal program was devised which successfully prevents the spread of FeLV and the development of FeLV diseases in the pet cat population. There is, at present, no evidence that FeLV infects humans living with FeLV infected cats.