Part III: Conservation and Management398
is tested (Barasona et al. 2013). Hence, camera trapping may
be a useful method for studying interactions by sampling the
complete array of individuals within an area, by monitoring
visits of several species at specific points (Figure 35.4) or by
providing behavioural insights into disease transmission sce-
nario (Harmsen et al. 2009; Payne et al. 2016). Finally, camera
traps can also provide specific information on diseased animals
(Figure 35.3) if symptoms of lesions can be detected externally
(Reyna-Hurtado et al. 2014).Biomarkers
It is assumed that close contact between different host popu-
lations can lead to transmission of pathogens between those
populations, if they are susceptible. The detection of antibodies
against diseases that have been eradicated in DP but remain pre-
sent in wild pigs (such as brucellosis or Aujeszky’s disease) have
been occasionally used as a raw indicator of potential spillover
contacts between DP and wild boar populations (Wyckoff et al.
2009; Wu et al. 2012). Some authors have used the detection
of viral agents such as HEV virus to infer potential contacts
between DP and wild species (Kukielka et al. 2015a). However,
the presence of antibodies or the antigen alone does not provideevidence of pathogen transmission between two populations,
and can hide potential spillover transmission from other wild-
life reservoirs or from a contaminated environment. Therefore,
a hypothetical transmission of pathogens between two popula-
tions or individuals should be proven by the phylogenetic prox-
imity of the pathogen strains found in both populations (Wu
et al. 2012; Jori et al. 2016), which requires isolation of the patho-
gen and subsequent analysis of genetic material with molecular
tools. However, it should be noted that finding a single evidence
of a shared pathogen between domestic and wild populations
does not necessarily mean that this transmission occurs fre-
quently. Its epidemiological significance will depend on the spa-
tial and temporal frequency of these events.
Such isolation of the pathogens under study is easier to
achieve if the latter can be detected in samples that do not require
invasive methods, such as the restraint and collection of biologi-
cal material from the individual wild animal. In that sense, the
use of faecal samples to obtain bacteria or pathogen Escherichia
coli to report potential gene flow of faecal flora between different
populations or individuals has been reported for different spe-
cies such as humans, wild ungulates, and domesticated species
(Rwego et al. 2008). Only recently, this technique has been tested
under experimental conditions between wild boars and DP, and
provided evidence that interactions between those populations
can also facilitate bacterial exchange in the case of suiform spe-
cies (Barth et al. 2017). Its use in field conditions is currently
under study, but preliminary results are promising.Impact of Diseases on Conservation
of Wild Pigs
A large proportion of the species of wild pigs known to date is
endangered or vulnerable. From that perspective, the contact
those rare and immunologically naive populations have with
new emerging pathogens can theoretically have devastating
consequences on the remaining populations of the species. In
this respect, white-lipped peccary populations are reported
to be exposed to severe population declines in most of their
distribution range in Latin America (Fragoso 2004; see also
Chapters 23, 24, and 25 in this book). One of the hypotheses
repeatedly suggested to explain those declines has been expo-
sure to pathogens and disease. Indeed, white-lipped peccaries
can aggregate in very large herds of several hundred individu-
als and infectious agents can easily spread among those herds
(Altrichter et al. 2012). However, to date, no evidence has ever
been provided to justify this hypothesis. The few veterinary sur-
veys undertaken on that species did not detect highly infectious
agents able to trigger massive die-offs, but rather pathogens that
could moderately affect its reproduction such as Leptospira spp.
and Brucella spp. (Karesh et al. 1998; de Freitas et al. 2010).
The circulation and potential impact of diseases on other
endangered pig species such as Hylochoerus spp., Catagonus
wagneri or many of the insular Asian wild pig species remains
unknown and deserves further investigation. Equally, the dissem-
ination of certain devastating pig diseases such as ASF into new
territories with large diversity of endangered wild swine popula-
tions is a cause of concern (Jori 2014). Many Asian countries haveFigure 35.5 Bushpig (Potamochoerus larvatus) captured at a baiting site in
Northern Uganda (photo by K. Sthäl). (A black and white version of this figure will
appear in some formats. For the colour version, please refer to the plate section.).03712:55:54