Wildlife tuberculosis in South African conservation areas: Implications and challenges

Abstract

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. #

Pulmonary Infection due to Mycobacterium bovis in a Black Rhinoceros (Diceros bicornis minor) in South Africa

“…In areas where M. bovis is found at high prevalence, it can cross the species and ecologic niche barrier and pose a threat to rare and endangered mammals by infecting them. It is known that African buffalo (Syncerus caffer) in some game parks have become infected with bovine tuberculosis (bTB) De Vos et al, 2001;Rodwell et al, 2001;Cousins et al, 2004;Michel et al, 2006), and buffalo in herds have become new maintenance species for bTB . A variety of ''spill-over'' species in the Kruger National Park have been found to be infected with bTB, such as chacma baboon (Papio ursinus), lion (Panthera leo), cheetah (Acinonyx jubatus), kudu (Tragelaphus strepsiceros), and leopard (Panthera pardus), as a result of the spreading infection of bTB in the buffalo herds in the park De Vos et al, 2001;Michel et al, 2009).…”

“…Genetic typing of the strain using spoligotyping (Kamerbeek et al, 1997) revealed a pattern consistent with M. bovis type SP8, which had been previously isolated from cattle in the Western and Eastern Cape, and also in Swaziland. The spacers that are deleted in the SP8 type are 3, 6, 8-12, 16, 39-43. For restriction fragment length polymorphism (RFLP) typing, the IS6110 and PGRS genetic markers were used for their high discriminatory power among South African M. bovis isolates (Michel et al, 2008(Michel et al, , 2009). The M. bovis isolated from the black rhino revealed a unique banding pattern when hybridized with the PGRS probe, despite some similarities with bovine isolates of the spoligotype SP8 from the Eastern Cape and the dominant M. bovis strain in the Hluhluwe-iMfolozi Park (HIP), respectively (Michel et al, 2008(Michel et al, , 2009) (data not shown).…”

“…The spacers that are deleted in the SP8 type are 3, 6, 8-12, 16, 39-43. For restriction fragment length polymorphism (RFLP) typing, the IS6110 and PGRS genetic markers were used for their high discriminatory power among South African M. bovis isolates (Michel et al, 2008(Michel et al, , 2009). The M. bovis isolated from the black rhino revealed a unique banding pattern when hybridized with the PGRS probe, despite some similarities with bovine isolates of the spoligotype SP8 from the Eastern Cape and the dominant M. bovis strain in the Hluhluwe-iMfolozi Park (HIP), respectively (Michel et al, 2008(Michel et al, , 2009) (data not shown). The IS6110 RFLP produced a banding pattern consistent with the C1 profile, which is one of the two most common and less discriminatory IS6110 profiles in cattle.…”

“…The IS6110 RFLP produced a banding pattern consistent with the C1 profile, which is one of the two most common and less discriminatory IS6110 profiles in cattle. Buffalo in HiP as well as the cattle isolate shown in Figure 3 were classified as C2 strains (Michel et al, 2008(Michel et al, , 2009). The same set of strains was subjected to an analysis of variable numbers of tandem repeat (VNTR) sequences, which again identified a unique genetic profile for the M. bovis from the black rhinoceros (Fig.…”

A review of bovine tuberculosis at the wildlife–livestock–human interface in sub-Saharan Africa

“…In southern Africa, bTB in free-ranging wildlife has been confirmed in South Africa [12,35], Zambia [36] and Zimbabwe [37], while the presence of the infection has been suspected in African buffalo in Botswana [38] although not confirmed using gold standard techniques. Furthermore, in Botswana, Alexander et al [39] reported the emergence of M. mungi, a new member of the M. tuberculosis complex in banded mongooses (Mungos mungo).…”