The Impact of Lentiviral Infections on African Lions: Captive versus Free-ranging Populations

摘要

Cross-reactive antibodies to feline immunodeficiency virus (FIV) were first reported in a captive African lion (Panthera led) in 1989 (1) and subsequently in free-ranging lions in 1992 (2). Seroprevalence in certain populations of lions in East and South Africa exceeded 80% (2-4). In North American zoos in the early 1990's, seroprevalence was estimated around 12-14% (3,5). Because large numbers of lions were not dying of classical acquired immune deficiency syndrome (AIDS), it was postulated that thevirus had co-evolved with its host to such an extent that it was relatively non-pathogenic. While phylogenetic analyses demonstrated that FIV, a lentivirus in the family Retroviridae, had been present in African lions for a long time, such molecular studies do not consider the slow, progressive course of infection characteristic of lentiviruses adapted to their host. Subsequent investigations evaluating phenotypic changes in lymphocyte subsets and long term management of captive, seropositive lions have shown that FIV affects both number and phenotype of T cells and can be neurotropic. The slow course of the infection does not impact reproduction so the population is not adversely impacted, but individuals within the population are at risk if a strong cell-mediated immune response is required or behavioral changes are incompatible with daily functions.