Chapter 31: Wild boar management in Europe349
adaptive management plans should be developed with commu-
nity involvement, at least in their design, with clear discussion of
the pros and cons of all available options. As well as population
control, such plans should also include a varied toolbox of non-
lethal preventive measures aimed at reducing both the attrac-
tiveness and accessibility of urban habitats for wild boar, as well
as mitigating specific conflicts through combined stakeholder
involvement.
Human and Animal Health Aspects
Is Wild Boar Abundance a Driver of Disease Dynamics?
During the last 30 years, the number of diseases notifications
in European wild boar has clearly increased (Table 31.1).
Correlations between disease intensity and persistence and
wild boar abundance were confirmed through retrospective or
experimental approaches (Boadella et al. 2012). However, many
other factors may have participated to increase disease risk in
that species. The effect of aggregation has been particularly well
documented in central–southern Spain where fencing, artificial
feeding and dryness are considered the main factors influencing
the prevalence and persistence of wild boar diseases (Vicente
et al. 2013). Some contagious diseases rather depend on social
patterns and habitat. For example, the spread and persistence of
classical swine fever (CSF) depends on the existence of large con-
nected populations, roughly dependent on forest structure and
barriers (roads or rivers), which facilitate between-groups trans-
mission much more than local density (Rossi et al. 2005). Multi-
host contagious diseases, such as bovine tuberculosis, may be
influenced by the use of space, connections and relative density
of each potential hosts (Barasona et al. 2014). Wild boar genet-
ics and co-infections may also deeply influence multi-pathogen
systems observed in natural populations (Diez-Delgado et al.
2014). Furthermore, human-borne diseases, more particu-
larly linked to wildlife translocation between hunting parks, is
an additional risk factor of wildlife outbreaks, which is mostly
underestimated and uncontrolled (Hars et al. 2015).
Factors Driving Transmissions from Wild Boar to Other Species
More than any other wildlife species, the European wild boar
(Sus scrofa) is faced with a wide range of pathogens transmis-
sible to other animal populations including humans (Ruiz Fons
et al. 2008; Meng et al. 2009). The central position of wild boar in
host–parasite systems possibly relies on its omnivorous diet, its
large distribution and home range, and its coevolution with par-
asites at the interface of human and domestic pigs (Goedbloed
et al. 2015). The increase of wild boar numbers and range is
supposed to represent a threat by increasing the risk of disease
emergence and persistence within wild boar populations first,
and second by increasing the risk of diseases spillover to other
animal populations, thus impacting human activities and health
(Gortázar et al. 2006; Meng et al. 2009). In Europe, wild boar
diseases may represent a threat for humans, pigs, extensive beef
cattle, and domestic carnivores. To a lesser extent, wild boar dis-
eases may represent an additional threat for some endangered
species, such as the Iberian lynx (Lynx pardinus) (Gortázar et al.
2008). On the other hand, wild boar may be a precious senti-
nel of environmental pollution or multiple antibiotic resistance
caused by human practices.
Disease transmission between wild boar and other mam-
mals may occur through direct transmission (e.g. Brucella suis
for the domestic pigs or Streptococcus suis in humans), environ-
mental contamination (e.g. bovine tuberculosis for cattle), or by
meat consumption (e.g. Trichinella or hepatitis E for humans,
Aujeszky’s disease for carnivores). The risk of transmission
between wild boar and other species thus relies not only on wild
boar numbers, but also on many factors extrinsic to wild boar
biology such as farming practices, human or animal biosafety,
public awareness, landscape structure, or climate change.How Can the Risk for Other Species be Decreased?
Preventing disease transmission between wild boar and other
species does not necessarily require the management of wild
boar, but preventing infective contact between them and target
populations. Regarding humans, biosafety may be improved by
increasing hunters’ awareness to gross lesions, by encouraging
the wearing of gloves when dressing carcasses, by promoting
Trichinella (microscopic worms infecting also humans) detec-
tion in wild boar meat and encouraging efficient cooking of
meat. Biosafety measures for protecting livestock are obviously
highly dependent on farming practices.
A second option for limiting pathogen transmission to live-
stock or humans is to control pathogen dynamics within wild
boar populations. This may be partly achieved by decreasing
environmental contaminations (e.g. organizing the destruction
of viscera, controlling swill feeding) and limiting aggregation
sources (e.g. artificial feeding, water points). The most efficient
tool for pathogen control is certainly vaccination, which has
been a satisfactory option for controlling classical swine fever
in many endemically infected populations (Rossi et al. 2015).
Obviously this method is not always achievable since vaccines
are not available for every disease, many steps from laboratory
to field application are necessary, and large-scale deployment
raises unexpected challenges and costs.
A last option is to manipulate wild boar numbers or move-
ments in order to break the chain of disease transmission. In
theory, density-dependent diseases should fade out under an ad-
hoc density threshold level and fences adequately used should
limit the spread of contagious diseases. In practice, cullingTable 31.1 Number of disease notifications in European wild boar
and confirmed spillover to other animal populations including humans
(sources: Pubmed, Google Scholar).Period Maximum number of
scientific publications
1980–84 623
1985–89 951
1990–94 1580
1995–99 3770
2000–04 6390
2005–09 11,000
2010–14 15,500.03312:55:50