Feline immunodeficiency virus (FIV) is a lentivirus in the Retroviridae family that causes lifelong
infection in domestic cats. The lentivirus of African lions (Panthera leo), referred to as FIVple, is endemic in certain
lion populations in eastern and southern Africa. Lentivirus infection leads to immunologic dysfunction and
immunosuppressive disease in domestic cats; however, little is known about the pathogenic effects of infection in
lions, nor about the epidemiologic impact on free-ranging and captive populations. Whole blood and serum
samples were collected opportunistically from free-ranging lions in Kruger National Park, Republic of South
Africa (RSA). Whole blood and serum samples were also collected from captive wild lions in the RSA. A nested
polymerase chain reaction (PCR) assay for detection of FIV was performed on all whole blood samples. In
addition, serum samples were tested for cross-reactive antibodies to domestic feline lentivirus antigens and puma
lentivirus synthetic envelope peptide antigen. The PCR assay successfully amplified the lion lentivirus from African
lions. The relative sensitivity and relative specificity were 79% and 100%, respectively, and the positive and negative
predictive values were 100% and 67%, respectively. This research represents the first study to compare genetic
material with antibody-based methods of lentivirus detection on lions in RSA. Using PCR as an additional
diagnostic test for FIV in lions will increase screening sensitivity and will allow viral characterization among
circulating isolates and monitoring of changes in the viral epidemiology within geographic regions and populations
over time