Connecting Global Priorities Biodiversity and Human Health

is a natural phenomenon, the widespread of use
of antimicrobials can create genetic selection
pressures for resistant strains. Dispersion of
antimicrobial drugs as well as genetic exchange
through ecological processes may also present
non-target environmental exposure in humans
and wildlife (Allen et al. 2010).
2.3.3 Wildlife trade and disease
Trade in wildlife involves the geographic
movement of hundreds of millions plants and
animals worldwide comprising an estimated
economic value of over US$ 300 billion per annum
(including both legal and illegal trade estimates)
(Ahlenius 2008). This trade is driven by consumer
demand for a multitude of products ranging from
traditional medicines, bushmeat, trophies, live
exotic pets, and foods. Within each of these broad
categories exists a wide range of specialty market
value chains that vary greatly in their motivating
economics, sociocultural origins, geographical
source and destination, transportation type
and route, trader and consumer profiles, species
composition and condition, and local and
international legality.
Trade in wildlife is illegal if it is contrary to the
laws of the participating nations or the limitations
on trade presented by the Convention on
International Trade of Endangered Species of Flora
and Fauna (CITES). Despite such protections, it
is estimated that illegal wildlife trade results in
a mean source population decline of 60–70% in
targeted species (Karesh et al. 2012). This failure
to protect vulnerable populations is a testament to
the evasiveness of the wildlife trafficking industry
from poacher to the black market, seemingly
impossible to monitor, let alone control. Further,
challenges in curbing illegal international wildlife
trade described by Conrad (2012) include high
demand and profit, cultural and societal traditions,
ambiguity of property rights, negative economic
incentives for bans, and inadequate enforcement.
Of additional concern is the fact that only CITESlisted
species garner much attempt at regulation
at all, while the ecological impact of harvest and
international trade of billions of non-CITES-listed
animals goes largely unassessed.
The hefty economic value of the global trade in
wildlife is rarely countered in the literature by
its costs to governments and the public for the
introduction of invasive species, as discussed
further in the following section. Likewise, several
significant zoonotic infectious diseases have
emerged in part due to the substantial human–
animal contact that occurs along the wildlife trade
chain, from harvest to end point. These diseases
have included SARS coronavirus (wet markets
in China), HIV (primate bushmeat hunting),
monkeypox virus (exotic pet trade), and H5N1 and
H7N9 avian influenza viruses (Karesh et al. 2005;
Gilbert et al. 2014). The global trade in wildlife
provides disease transmission mechanisms that
not only result in human and animal health
threats but also damages to international trade,
agricultural livelihoods, and global food security.
There is minimal overall health regulation of
the wildlife trade in comparison to agricultural
trade, and such work falls between regulatory
authorities of national ministries (e.g. agricultural,
environmental and public health) and international
regulatory organizations. Wildlife trade is complex
and multimodal and does not present equal
risk to environmental, agricultural and human
health. Thus the threat of disease emergence
from the wildlife trade and the socioeconomic
and behavioural factors that contribute to it
cannot be defined with one overarching risk
assessment. Rather, specific market value chain
types require targeted evaluation and tailored
intervention policies that would put measures
in place to facilitate relatively benign commerce
while establishing the necessary measures to
minimize practices that are damaging to the global
environment and health.
2.3.4 Implications of biotic exchange
(invasive alien species)
The term invasive alien species (IAS) refers to a
species, sub-species or other taxon of organism,
introduced by human action outside its natural
past or present distribution, and whose introduction,
establishment and spread threatens biological
diversity or ecosystem integrity. Introductions can
occur either intentionally or accidentally, and the
140 Connecting Global Priorities: Biodiversity and Human Health