Tuberculosis, caused by Mycobacterium bovis, was first diagnosed in African buffalo in South Africa's Kruger National Park in 1990. Over the past 15 years the disease has spread northwards leaving only the most northern buffalo herds unaffected. Evidence suggests that 10 other small and large mammalian species, including large predators, are spillover hosts. Wildlife tuberculosis has also been diagnosed in several adjacent private game reserves and in the Hluhluwe-iMfolozi Park, the third largest game reserve in South Africa.The tuberculosis epidemic has a number of implications, for which the full effect of some might only be seen in the longterm. Potential negative long-term effects on the population dynamics of certain social animal species and the direct threat for the survival of endangered species pose particular problems for wildlife conservationists. On the other hand, the risk of spillover infection to neighboring communal cattle raises concerns about human health at the wildlife-livestock-human interface, not only along the western boundary of Kruger National Park, but also with regards to the joint development of the Greater Limpopo Transfrontier Conservation Area with Zimbabwe and Mozambique. From an economic point of view, wildlife tuberculosis has resulted in national and international trade restrictions for affected species. The lack of diagnostic tools for most species and the absence of an effective vaccine make it currently impossible to contain and control this disease within an infected free-ranging ecosystem. Veterinary researchers and policy-makers have recognized the need to intensify research on this disease and the need to develop tools for control, initially targeting buffalo and lion. #

VP1 gene sequences of SAT-2 type foot-and-mouth disease (FMD) viruses recovered from impala and African buffalo in the Kruger National Park (KNP) were used to determine intra- and interspecies relationships of viruses circulating in these wildlife populations. On this basis five distinct lineages of SAT-2 virus were identified in routine sampling of oesophageopharyngeal epithelium from buffalo between 1988 and 1996. Different lineages were associated with discrete geographic sampling localities. Over the period 1985-95, four unrelated epizootics occurred in impala in defined localities within the KNP. Evidence for natural transmission of FMD between buffalo and impala is presented for the most recent 1995 outbreak, with data linking the 1985 and 1988/9 impala epizootics to viruses associated with specific buffalo herds.

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Transmission of a plaque-purified SAT-2 foot-andmouth disease virus (FMDV) occurred erratically from artificially infected African buffaloes in captivity to susceptible buffaloes and cattle in the same enclosure; in some instances transmission occurred only after contact between persistently infected carriers and susceptible animals lasting a number of months. Because the rate at which FMDV mutations accumulated in persistently infected buffaloes was approximately linear (1.64% nucleotide substitutions per year over the region of the 1D gene sequenced), both buffaloes and cattle that became infected some months after the start of the experiment were infected with viruses that differed from the original clone. The nucleotide differences were reflected in significant antigenic change. A SAT-1 FMDV from a separate experiment inadvertently infected some of the buffalo in the SAT-2 experiment. The SAT-1 FMDV also accumulated mutations at a constant rate in individual buffaloes (1.54% nucleotide changes per year) but the resultant antigenic variation was less than for SAT-2. It is concluded that persistently infected buffaloes in the wild constantly generate variants of SAT-1 and SAT-2 which explains the wide range of genomic and antigenic variants which occur in SAT-1 and SAT-2 viruses in southern Africa.

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A retrospective serosurvey of multi-host feline and canine viruses among carnivore species in southern Africa (n = 1018) identified widespread pathogen exposure even in remote protected areas. In contrast to morality experienced in East African predators, canine distemper virus (CDV) infection among African wild dogs (Lycaon pictus) in Botswana was not associated with identifiable change in pup survivorship or disease related mortality of adults. A disease outbreak of unknown aetiology occurred in the same population over 4 weeks in 1996. Outbreak boundaries coincided with ecotones, not the spatial distribution of contiguous packs, highlighting the potential importance of landscape heterogeneities in these processes. Direct management of pathogens in domestic animal reservoirs is complicated by the apparent complexity of pathogen maintenance and transmission in these large systems. Conservation effort should be focused at securing large metapopulations able to compensate for expected episodic generalist pathogen RésuméAu travers d'une étude sérologique rétrospective de virus affectant plusieurs espèces de carnivores d'Afrique du sud (n = 1073), nous montrons une exposition étendue aux pathogènes dans cette région jusque dans des parties reculées de zones protégées. Au contraire de la mortalité observée chez les prédateurs Est africains, les infections au virus de la maladie de Carre chez les chiens sauvage du Botswana n'était pas associée à un changement significatif de la survie des chiots. L'éruption d'une pathologie d'étiologie inconnue s'est déclenchée chez les chiens sauvages dans le delta de l 'Okavango, au Botswana (1996). Les frontières de l'épidémie coïncidaient plus avec les écotones qu'avec la distribution géographique des meutes, ce qui souligne l'importance de l'hétérogénéité des paysages dans ces dynamiques. La gestion directe des pathogènes dans les réservoirs d'animaux domestiques se trouve compliquée par l'apparente complexité du maintient et de la transmission de pathogènes dans ces vastes systèmes. Les efforts de conservation devraient être portés sur la sécurisation de grandes métapopulations capable de compenser des invasions épisodiques prédic-tibles de pathogènes généralistes, ainsi que sur les causes de déclin de populations sauvages telles que des pertes d'habitat ou des conflits avec des activités humaines. #

Bovine tuberculosis (BTB), caused by Mycobacterium bovis, is a disease that was introduced relatively recently into the Kruger National Park (KNP) lion population. Feline immunodeficiency virus (FIV ple ) is thought to have been endemic in lions for a much longer time. In humans, co-infection between Mycobacterium tuberculosis and human immunodeficiency virus increases disease burden. If BTB were to reach high levels of prevalence in lions, and if similar worsening effects would exist between FIV ple and BTB as for their human equivalents, this could pose a lion conservation problem. We collected data on lions in KNP from 1993 to 2008 for spatio-temporal analysis of both FIV ple and BTB, and to assess whether a similar relationship between the two diseases exists in lions. We found that BTB prevalence in the south was higher than in the north (72 versus 19% over the total study period) and increased over time in the northern part of the KNP (0-41%). No significant spatio-temporal differences were seen for FIV ple in the study period, in agreement with the presumed endemic state of the infection. Both infections affected haematology and blood chemistry values, FIV ple in a more pronounced way than BTB. The effect of co-infection on these values, however, was always less than additive. Though a large proportion (31%) of the lions was co-infected with FIV ple and M. bovis, there was no evidence for a synergistic relation as in their human counterparts. Whether this results from different immunopathogeneses remains to be determined.