Worldwide Prevalence of Lentivirus Infection in Wild Feline Species: Epidemiologic and Phylogenetic Aspects

The natural occurrence of lentiviruses closely related to feline immunodeficiency virus (FIV) in nondomestic felid species is shown here to be worldwide. Cross-reactive antibodies to FIV were common in several free-ranging populations of large cats, including East African lions and cheetahs of the Serengeti ecosystem and in puma (also called cougar or mountain lion) populations throughout North America. Infectious puma lentivirus (PLV) was isolated from several Florida panthers, a severely endangered relict puma subspecies inhabiting the Big Cypress Swamp and Everglades ecosystems in southern Florida. Phylogenetic analysis of PLV genomic sequences from disparate geographic isolates revealed appreciable divergence from domestic cat FIV sequences as well as between PLV sequences found in different North American locales. The level of sequence divergence between PLV and FIV was greater than the level of divergence between human and certain simian immunodeficiency viruses, suggesting that the transmission of FIV between feline species is infrequent and parallels in time the emergence of HIV from simian ancestors

Genetic Factors Leading to Chronic Epstein–Barr Virus Infection and Nasopharyngeal Carcinoma in South East China: Study Design, Methods and Feasibility

Nasopharyngeal carcinoma (NPC) is a complex disease caused by a combination of Epstein-Barr virus chronic infection, the environment and host genes in a multi-step process of carcinogenesis. The identity of genetic factors involved in the development of chronic Epstein-Barr virus infection and NPC remains elusive, however. Here, we describe a two-phase, population-based, case-control study of Han Chinese from Guangxi province, where the NPC incidence rate rises to a high of 25-50 per 100,000 individuals. Phase I, powered to detect single gene associations, enrolled 984 subjects to determine feasibility, to develop infrastructure and logistics and to determine error rates in sample handling. A microsatellite screen of Phase I study participants, genotyped for 319 alleles from 34 microsatellites spanning an 18-megabase region of chromosome 4 (4p15.1-q12), previously implicated by a linkage analysis of familial NPC, found 14 alleles marginally associated with developing NPC or chronic immunoglobulin A production (p = 0.001-0.03). These associations lost significance after applying a correction for multiple tests. Although the present results await confirmation, the Phase II study population has tripled patient enrolment and has included environmental covariates, offering the potential to validate this and other genomic regions that influence the onset of NPC

The Consequences of Demographic Reduction and Genetic Depletion in the Endangered Florida Panther

The Florida panther has recently suffered severe range and demographic contraction, leaving a remarkably low level of genetic diversity. This exerts a severe fitness cost, manifested by spermatozoal defects, cryptorchidism, cardiac abnormalities and infectious diseases that threaten the survival of the subspecies

Exposure to FIV and FIPV in Wild and Captive Cheetahs

Two RNA-containing viruses, feline infectious peritonitis virus (FIPV) and feline immunodeficiency virus (FIV), have been observed to infect cheetahs. Although both viruses cause lethal immunogenetic pathology in domestic cats, only FIPV has documented pathogenesis in cheetahs. We summarize and update here a worldwide survey of serum and plasma from cheetah and other nondomestic felids for antibodies to FIV and FIPV, based on Western blot and immunofluorescence assays. FIPV exposure shows an acute pattern with recognizable outbreaks in several zoological facilities, but is virtually nonexistent in sampled free-ranging populations of cheetahs. FIV is more endemic in certain natural cheetah populations, but infrequent in zoological collections. FIV exposure was also seen in lions, bobcats, leopards, snow leopards, and jaguars. FIV causes T-cell lymphocyte depletion and associated diseases in domestic cats, but there is little direct evidence for FIV pathology in exotic cats to date. Because of the parallels with a high incidence of simian immunodeficiency virus in free-ranging African primates without disease, the cat model may also reflect historic infections that have approached an evolutionary balance between the pathogen and immune defenses of their feline host species

Molecular Genetic Identification of a Mexican Onza Speciment as a Puma (Puma concolor)

Tissue samples from an alleged Mexican Onza, shot in the western Sierra Madre in 1986, were subjected to several biochemical assays in an attempt to determine the specimen\u27s relationship to felid species of North America. Protein analyses included isoenzyme electrophoresis and albumin isoelectric focusing. Mitochondrial DNA was assayed for restriction fragment lengths with 28 restriction enzymes, and the ND5 gene was sequences. The resulting protein and mitochondrial DNA characteristics of the Onza were indistinguishable from those of North American pumas

Case Study of a Population Bottleneck: Lions of the Ngorongoro Crater

Lions in the Ngorongoro Crater, Tanzania, form a small and naturally isolated population In 1962, the Crater lions suffered an epizootic that reduced the population to nine females arui one male. An additional seven males apparently immigrated into the Crater in 1964-1965. but there has been no further immigration into the Crater in the past 25 years. By 1975, the population had recovered to its current level of 75—125 animals. All members of the current Crater population are descended from only 15 founders, and over the years there has been considerable variance in the reproductive success of both sexes. The Crater was probably colonized by lions from the nearby Serengeti ecosystem and the contemporary Crater lion population shows a significant lack of genetic diversity compared to the much larger Serengeti population The detailed reproductive history of the Crater population was incorporated into a series of stochastic computer simulations that generated distributions of expected allele frequencies under different sets of initial conditions. The simulations suggest that the Crater population may have passed through previous bottlenecks before 1962 but that the level of heterozygosity in the breeding population has been declining since the mid-1970s, regardless of the population\u27s genetic composition in the 1960s. High levels of inbreeding are correlated with increased levels of sperm abnormality in lions and there is evidence that the reproductive performance of the Crater lions has decreased as a result of decreasing heterozygosit

Seroprevalence of Toxoplasma gondii in American Free-Ranging or Captive Pumas (Felis concolor) and Bobcats (Lynx rufus)

Toxoplasma gondii is a major zoonotic agent infecting a wide range of mammals, including wild felids. Like domestic cats, wild felids are involved in the complete infective cycle of T. gondii, as they can host in their gastrointestinal tract sexually mature parasites and shed infective oocysts in their feces. In order to evaluate the importance of this wildlife reservoir, 438 serum samples collected between 1984 and 1999 from 438 pumas (Felis concolor) and from 58 bobcats (Lynx rufus) from North America, Central America and South America were screened for antibodies to T. gondii. The overall prevalence of T. gondii antibodies was 22.4% in pumas and 51.7% in bobcats, with regional variations. Adults were more likely to be seropositive than juveniles and kittens (prevalence ratio (PR)=2.15; 95% confidence interval (CI)=1.15, 4.04). In the US, pumas from the southwestern states (Arizona, California and New Mexico) were more likely to be seropositive for T. gondii (PR=2.61; 95% CI=1.32–5.18) than pumas from the northwestern and mountain states (Colorado, Idaho, Oregon, Utah and Wyoming). Male pumas from the US were more likely to be seropositive than females (PR=2.08; 95% CI=1.11–3.92), whereas female pumas from Mexico, Central America and South America were more likely to be seropositive than female pumas from Canada and the US (PR=2.49; 95% CI=1.09–5.69). Captive pumas were also more likely to be seropositive (21.7%, 29/92) for T. gondii than free-ranging animals (19.9%, 69/346) (PR=1.85; 95% CI=1.06, 3.17)

Prevalence of antibodies to feline parvovirus, calicivirus, herpesvirus, coronavirus, and immunodeficiency virus and of feline leukemia virus antigen and the interrelationship of these viral infections in free-ranging lions in east Africa

While viral infections and their impact are well studied in domestic cats, only limited information is available on their occurrence in free-ranging lions. The goals of the present study were (i) to investigate the prevalence of antibodies to feline calicivirus (FCV), herpesvirus (FHV), coronavirus (FCoV), parvovirus (FPV), and immunodeficiency virus (FIV) and of feline leukemia virus (FeLV) antigen in 311 serum samples collected between 1984 and 1991 from lions inhabiting Tanzania's national parks and (ii) to evaluate the possible biological importance and the interrelationship of these viral infections. Antibodies to FCV, never reported previously in free-ranging lions, were detected in 70% of the sera. In addition, a much higher prevalence of antibodies to FCoV (57%) was found than was previously reported in Etosha National Park and Kruger National Park. Titers ranged from 25 to 400. FeLV antigen was not detectable in any of the serum samples. FCoV, FCV, FHV, and FIV were endemic in the Serengeti, while a transient elevation of FPV titers pointed to an outbreak of FPV infection between 1985 and 1987. Antibody titers to FPV and FCV were highly prevalent in the Serengeti (FPV, 75%; FCV, 67%) but not in Ngorongoro Crater (FPV, 27%; FCV, 2%). These differences could be explained by the different habitats and biological histories of the two populations and by the well-documented absence of immigration of lions from the Serengeti plains into Ngorongoro Crater after 1965. These observations indicate that, although the pathological potential of these viral infections seemed not to be very high in free-ranging lions, relocation of seropositive animals by humans to seronegative lion populations must be considered very carefully

Viruses of the Serengeti: patterns of infection and mortality in African lions

1. We present data on the temporal dynamics of six viruses that infect lions (Panthera leo) in the Serengeti National Park and Ngorongoro Crater, Tanzania. These populations have been studied continuously for the past 30 years, and previous research has documented their seroprevalence for feline herpesvirus, feline immunodeficiency virus (FIV), feline calicivirus, feline parvovirus, feline coronavirus and canine distemper virus (CDV). A seventh virus, feline leukaemia virus (FeLV), was absent from these animals. 2. Comprehensive analysis reveals that feline herpesvirus and FIV were consistently prevalent at high levels, indicating that they were endemic in the host populations. Feline calici-, parvo- and coronavirus, and CDV repeatedly showed a pattern of seroprevalence that was indicative of discrete disease epidemics: a brief period of high exposure for each virus was followed by declining seroprevalence. 3. The timing of viral invasion suggests that different epidemic viruses are associated with different minimum threshold densities of susceptible hosts. Furthermore, the proportion of susceptibles that became infected during disease outbreaks was positively correlated with the number of susceptible hosts at the beginning of each outbreak. 4. Examination of the relationship between disease outbreaks and host fitness suggest that these viruses do not affect birth and death rates in lions, with the exception of the 1994 outbreak of canine distemper virus. Although the endemic viruses (FHV and FIV) were too prevalent to measure precise health effects, there was no evidence that FIV infection reduced host longevity

Molecular Genetic Insights on Cheetah (Acinonyx jubatus) Ecology and Conservation in Namibia

The extent and geographic patterns of molecular genetic diversity of the largest remaining free-ranging cheetah population were described in a survey of 313 individuals from throughout Namibia. Levels of relatedness, including paternity/maternity (parentage), were assessed across all individuals using 19 polymorphic microsatellite loci, and unrelated cheetahs (n = 89) from 7 regions were genotyped at 38 loci to document broad geographical patterns. There was limited differentiation among regions, evidence that this is a generally panmictic population. Measures of genetic variation were similar among all regions and were comparable with Eastern African cheetah populations. Parentage analyses confirmed several observations based on field studies, including 21 of 23 previously hypothesized family groups, 40 probable parent/offspring pairs, and 8 sibling groups. These results also verified the successful integration and reproduction of several cheetahs following natural dispersal or translocation. Animals within social groups (family groups, male coalitions, or sibling groups) were generally related. Within the main study area, radio-collared female cheetahs were more closely interrelated than similarly compared males, a pattern consistent with greater male dispersal. The long-term maintenance of current patterns of genetic variation in Namibia depends on retaining habitat characteristics that promote natural dispersal and gene flow of cheetahs