Feline Immunodeficiency Virus and Puma Lentivirus in Florida panthers (Puma concolor coryi): Epidemiology and Diagnostic Issues

Abstract

This study documents the seroprevalence of feline immunodeficiency virus (FIV) and puma lentivirus (PLV) in free-ranging and captive Florida panthers (Puma concolor coryi) (n = 51) and translocated Texas cougars (P. concolor stanleyana) (n = 10) from 1985 to 1998. The sera were tested for anti-FIV antibodies by enzyme-linked immunosorbent assay (ELISA) and Western blot tests. The ELISAs were read kinetically (KELA) and the sera were retrospectively examined by PLV peptide ELISA. Eleven panthers and one cougar were positive by KELA; 4 panthers and 4 cougars were equivocal; 35 panthers and 5 cougars were negative; and 1 panther had no data. Seven of the 11 KELA-positive panthers were also positive by Western blot tests and all but one were positive by PLV peptide ELISA. Ten KELA-negative and Western blot-negative cats, were positive by PLV peptide ELISA. KELA results varied within cats from one sample period to the next, but PLV peptide ELISA results were consistent. Territorial sympatry and mating behaviour, noted from radiotelemetry location data on the cats, may have contributed to viral transmission between seropositive animals. These findings suggest that Florida panthers and the introduced Texas cougars have been exposed to FIV and/or PLV.

Variability in assays used for detection of lentiviral infection in bobcats (Lynx rufus), pumas (Puma concolor), and ocelots (Leopardus pardalis)

“…Further, although the true infection status of wild individuals is difficult to determine conclusively, it appears unlikely that PLV immunoblot produces false positive results. These findings are consistent with those of previous studies that have demonstrated that immunoblot is superior to other techniques (e.g., ELISA, IFA, PCR) for detecting lentiviral infection in primates and felids (VandeWoude and Apetrei, 2006), and that wild felid lentivirus-based assays are more sensitive for detecting lentiviral infection in wild felids than domestic cat FIV assays (Osofsky et al, 1996;Van Vuuren et al, 2003;Miller et al, 2006). We recommend that a PLV immunoblot be used for screening of bobcat, puma, or ocelot populations should only one assay be used for screening.…”

“…However, several captive African lions (Panthera leo) have manifested clinical signs or hematologic abnormalities associated with lentiviral infection (Poli et al, 1995;Spencer et al, 1995;Bull et al, 2003). Although few studies have investigated the clinical consequences of lentiviral infection in wild felids, a recent study has demonstrated that infection in wild African lions (P. leo) and pumas causes CD4+ lymphocyte depression (Miller et al, 2006;Roelke et al, 2006). Further, feline leukemia virus (FeLV) infection in feral domestic cats (Felis catus) has been associated with FIV infection (Luria et al, 2004), and FeLV has recently been reported in the endangered Florida panther (Puma concolor coryi) population (Cunningham et al, 2004), posing an additional threat to the persistence of this subspecies.…”

“…Study of lentivirus in wild African felids and Florida panthers suggests that assays using antigen from puma lentivirus (PLV) are more sensitive and specific than FIVbased assays, including immunoblot, IFA, and ELISA (Osofsky et al, 1996;Van Vuuren et al, 2003;Miller et al, 2006). These assays are likely to vary in sensitivity in wild species because of the substantial genetic variability among the lentiviruses infecting the different species (Troyer et al, 2005).…”

Going Wild: Lessons from Naturally Occurring T-Lymphotropic Lentiviruses

“…For example, Serengeti African lions are nearly 100% seropositive (53,375), as are pumas in Wyoming that are over 4 years of age (41). Pumas in Montana have maintained an approximate seroprevalence rate of 20% over time (40), similar to seroprevalence rates detected in Florida panthers and in cougars from Washington State (116,252). In contrast, significant numbers of free-ranging Asiatic lions or those found in Etosha Pan (Namibia) were all seronegative (53,356,375).…”

“…The antibody response following nondomestic cat FIV infection is generally vigorous, although approximately 20% of animals exhibit an indeterminant antibody response, as evaluated by Western blot analysis (252,376). This is likely at least partially due to poor cross-reactivity between viral antigens prepared in vitro and naturally occurring viruses, particularly when an antigen from one species is used to detect antibodies to another.…”