Fever is caused by a monotypic Asfar virus, and until recently its distribution has
been limited to sub-Saharan Africa, with occasional excursions into Spain and
Sardinia. In 2007, ASF was introduced to the eastern European country of Georgia,
in swill originating from a ship that had arrived from Mozambique (Rowlands et al.
2008). From Georgia, the disease spread northwards to Belarus, Ukraine, and
western Russia, affecting both wild boars and domestic pigs. In 2014, the disease
spread into Lithuania, and from there onto Latvia, Estonia and Poland (Śmietanka
et al. 2016). The disease appears to be spread by wild boars, but the movement of
carcasses and domestic pig products also appears to play an important role. The ASF
virus is an extremely robust virus that can survive prolonged periods outside a host,
and survive indefinitely in frozen pig products. It only affects pigs, and may result in
>90% mortality and there is currently no treatment or effective vaccine (Penrith
et al. 2004). The only control options available are to control the movement of pigs
and pig products, and slaughter infected herds, followed by burying or incinerating
infected carcasses. The disease has now spread to Romania, the Czech Republic and
Luxembourg, bringing it ever closer to the major pig-producing countries of Germany, Holland and Denmark (OIE 2018). This is of grave concern to the EU and the
pig producers in those countries. What is even concerning is that the disease has now
entered China from the north, and outbreaks have been reported in 21 locations in
China. China is the biggest producer of pigs in the world, and pork is a staple protein
across the whole of Southeast Asia. We are thus now faced with an alien viral
infection which has spread through several naïve ecosystems and is having profound
effects on wildlife (wild boar) and the domestic pig industry. There is every reason to
believe this pandemic could have catastrophic outcomes, similar to the rinderpest
outbreaks of the eighteenth, nineteenth and early twentieth centuries.
10.5 The Future
There is little doubt that as humans continue to expand their range into wild areas,
new diseases will emerge and jump the species barrier to affect novel hosts.
Examples of this are the haemorrhagic fevers such as Ebola, where frequent outbreaks have been recorded in Africa. In many cases, these risks will come from
disrupted territories and more contact with animal species such as, but not limited to,
bats (Marsh and Wang 2012) and rodents. Zoonotic disease is particularly likely
from such activities and it is estimated that most infectious diseases that have
emerged in the last 6 decades originated in wildlife (FAO 2013). The ubiquitous
and diverse nature of influenza viruses suggests almost certain outbreaks of such
pandemics in future, whether swine, avian or of the human variety.
Many diseases will arise from direct contact, but some will be driven by vectors
such as mosquitos (Farajollahi et al. 2011) or ticks. Climate change is likely to allow
expansion of vector areas, allowing potential for spread of diseases that previously
could not be spread. There is a discrepancy in the way we look at diseases versus
climate change. While climate change is studied at a global level, diseases are
usually considered at a local or ecosystem level. Such thinking goes hand-in-hand
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L. van Helden et al.
been limited to sub-Saharan Africa, with occasional excursions into Spain and
Sardinia. In 2007, ASF was introduced to the eastern European country of Georgia,
in swill originating from a ship that had arrived from Mozambique (Rowlands et al.
2008). From Georgia, the disease spread northwards to Belarus, Ukraine, and
western Russia, affecting both wild boars and domestic pigs. In 2014, the disease
spread into Lithuania, and from there onto Latvia, Estonia and Poland (Śmietanka
et al. 2016). The disease appears to be spread by wild boars, but the movement of
carcasses and domestic pig products also appears to play an important role. The ASF
virus is an extremely robust virus that can survive prolonged periods outside a host,
and survive indefinitely in frozen pig products. It only affects pigs, and may result in
>90% mortality and there is currently no treatment or effective vaccine (Penrith
et al. 2004). The only control options available are to control the movement of pigs
and pig products, and slaughter infected herds, followed by burying or incinerating
infected carcasses. The disease has now spread to Romania, the Czech Republic and
Luxembourg, bringing it ever closer to the major pig-producing countries of Germany, Holland and Denmark (OIE 2018). This is of grave concern to the EU and the
pig producers in those countries. What is even concerning is that the disease has now
entered China from the north, and outbreaks have been reported in 21 locations in
China. China is the biggest producer of pigs in the world, and pork is a staple protein
across the whole of Southeast Asia. We are thus now faced with an alien viral
infection which has spread through several naïve ecosystems and is having profound
effects on wildlife (wild boar) and the domestic pig industry. There is every reason to
believe this pandemic could have catastrophic outcomes, similar to the rinderpest
outbreaks of the eighteenth, nineteenth and early twentieth centuries.
10.5 The Future
There is little doubt that as humans continue to expand their range into wild areas,
new diseases will emerge and jump the species barrier to affect novel hosts.
Examples of this are the haemorrhagic fevers such as Ebola, where frequent outbreaks have been recorded in Africa. In many cases, these risks will come from
disrupted territories and more contact with animal species such as, but not limited to,
bats (Marsh and Wang 2012) and rodents. Zoonotic disease is particularly likely
from such activities and it is estimated that most infectious diseases that have
emerged in the last 6 decades originated in wildlife (FAO 2013). The ubiquitous
and diverse nature of influenza viruses suggests almost certain outbreaks of such
pandemics in future, whether swine, avian or of the human variety.
Many diseases will arise from direct contact, but some will be driven by vectors
such as mosquitos (Farajollahi et al. 2011) or ticks. Climate change is likely to allow
expansion of vector areas, allowing potential for spread of diseases that previously
could not be spread. There is a discrepancy in the way we look at diseases versus
climate change. While climate change is studied at a global level, diseases are
usually considered at a local or ecosystem level. Such thinking goes hand-in-hand
266
L. van Helden et al.