Update on Canine and Feline Blood Donor Screening for Blood-Borne Pathogens

Wardrop, K.J.; Birkenheuer, A.; Blais, M.C.; Callan, M.B.; Kohn, B.; Lappin, M.R.; Sykes, J.

Feline Immunodeficiency Virus. Feline Immunodeficiency Virus (FIV) is transmitted primarily through bite wounds, but it can be readily transmitted via inoculation of infected blood. 104,105 Testing of donor cats for FIVspecific antibodies by ELISA (which uses immobilized FIV core proteins p24 gag and p15 to capture antibodies in blood) is recommended, and all seropositive cats should be excluded from the donor pool. Cats vaccinated against FIV also will be seropositive. Definitive differentiation of infected from vaccinated cats is challenging, because virus isolation, the gold standard for diagnosis of FIV infection, is time-consuming and expensive. Real-time quantitative PCR assays for FIV are moderately sensitive and highly specific for FIV infection, but positive results have occurred in uninfected, vaccinated cats. 106 Therefore, until reliable approaches are available that conclusively discriminate naturally infected cats from vaccinated cats, the panel recommends that all seropositive cats, including vaccinated cats, be excluded from the donor pool. Free-roaming cats also should be excluded from donor programs.