than normal (Keet et al. 2000). Although it is clear that BTB has caused lion
mortality in KNP (Michel et al. 2006), which would suggest a projected decrease
in population (Keet et al. 2009), others assert that at a population level this is unlikely
(Ferreira and Funston 2010; Kosmala et al. 2016). However, since lions are already
facing threats posed by habitat loss, poaching and feline immunodeficiency virus
(Renwick et al. 2007), the cumulative effect these factors plus BTB on their
population has the potential to be devastating. The global lion population has
decreased by 43% over the last three generations. Lion populations in southern
Africa are the most stable, and it is the only remaining area where lions are not
persecuted to the extent of being classified as endangered by the IUCN (Bauer et al.
2016). The health of lions in southern Africa may therefore be important for
preserving their species in the wild.
Control of BTB once it is established in wildlife populations is challenging, but a
reduction in disease prevalence has been seen in HiP after the use of an intensive
programme to test buffalo and cull those that test positive (Renwick et al. 2007;
Cooper 2012). While this approach is of benefit to the population within HiP, it is
still an infected population and there are therefore restrictions on translocations of
animals out of the park. This disrupts programmes which aim to increase genetic
diversity of wildlife species by moving animals between isolated conservation areas.
There is currently no effective vaccine to combat tuberculosis either in animals or
humans.
A voluntary testing programme exists for cattle herds in South Africa, so eradicating BTB in cattle is probably unlikely. African Buffalo in the country have to be
tested before each translocation, to try and keep BTB out of other parks, but
warthogs and Greater Kudu can travel long distance and spread over the country if
they wish, therefore are problematic species if they are maintenance hosts.
Although infection of South African wildlife was originally caused by cattle,
BTB-infected wildlife now pose a risk to domestic livestock. The existence of the
disease in wildlife could, therefore, cause conservation efforts to be viewed negatively by livestock owners living close to conservation areas. Ecotourism could also
be negatively affected by the influence of the disease on wildlife populations, or by
perceptions of tourists when encountering diseased animals. Furthermore, conservation resources are extremely limited and can be allocated to disease control only
when captured animals are earmarked for movement to a new area.
BTB is an example of an invasive disease whose effects in wildlife systems are, as
yet, unclear. However, that changes in the population structure of some species
within an ecosystem harbouring BTB will occur, seems likely. In the case of
domestic stock, however, there are many consequences of disease, amongst which
are economic costs to owners.
10 Pathogens of Vertebrate Animals as Invasive Species: Insights from South Africa
259
mortality in KNP (Michel et al. 2006), which would suggest a projected decrease
in population (Keet et al. 2009), others assert that at a population level this is unlikely
(Ferreira and Funston 2010; Kosmala et al. 2016). However, since lions are already
facing threats posed by habitat loss, poaching and feline immunodeficiency virus
(Renwick et al. 2007), the cumulative effect these factors plus BTB on their
population has the potential to be devastating. The global lion population has
decreased by 43% over the last three generations. Lion populations in southern
Africa are the most stable, and it is the only remaining area where lions are not
persecuted to the extent of being classified as endangered by the IUCN (Bauer et al.
2016). The health of lions in southern Africa may therefore be important for
preserving their species in the wild.
Control of BTB once it is established in wildlife populations is challenging, but a
reduction in disease prevalence has been seen in HiP after the use of an intensive
programme to test buffalo and cull those that test positive (Renwick et al. 2007;
Cooper 2012). While this approach is of benefit to the population within HiP, it is
still an infected population and there are therefore restrictions on translocations of
animals out of the park. This disrupts programmes which aim to increase genetic
diversity of wildlife species by moving animals between isolated conservation areas.
There is currently no effective vaccine to combat tuberculosis either in animals or
humans.
A voluntary testing programme exists for cattle herds in South Africa, so eradicating BTB in cattle is probably unlikely. African Buffalo in the country have to be
tested before each translocation, to try and keep BTB out of other parks, but
warthogs and Greater Kudu can travel long distance and spread over the country if
they wish, therefore are problematic species if they are maintenance hosts.
Although infection of South African wildlife was originally caused by cattle,
BTB-infected wildlife now pose a risk to domestic livestock. The existence of the
disease in wildlife could, therefore, cause conservation efforts to be viewed negatively by livestock owners living close to conservation areas. Ecotourism could also
be negatively affected by the influence of the disease on wildlife populations, or by
perceptions of tourists when encountering diseased animals. Furthermore, conservation resources are extremely limited and can be allocated to disease control only
when captured animals are earmarked for movement to a new area.
BTB is an example of an invasive disease whose effects in wildlife systems are, as
yet, unclear. However, that changes in the population structure of some species
within an ecosystem harbouring BTB will occur, seems likely. In the case of
domestic stock, however, there are many consequences of disease, amongst which
are economic costs to owners.
10 Pathogens of Vertebrate Animals as Invasive Species: Insights from South Africa
259