32 H. Yahyaoui Azami and J. Zinsstag
in developing countries (Fried et al., 2010).
Moreover, OH courses are available in many
universities, non-governmental organizations
and government agencies, for example, the
University of Edinburgh, London School of
Hygiene and Tropical Medicine, Swiss Tropical
and Public Health Institute, and many other
universities and institutes.
Examples of OH approaches include a
vaccination campaign in Chad for both pastoral-
ists (vaccination against diphtheria, whooping
cough, tetanus and against polio) and their
livestock (vaccination against anthrax, pasteu-
rellosis, blackleg and contagious bovine pleuro-
pneumonia), in addition to the delivery of
healthcare. This was a successful intervention
integrating human and animal health workers,
where this joint action allowed a reduction of
costs by 15% compared to a separate campaign
(Bechir et al., 2003; Schelling et al., 2007).
Moreover, it has been validated in a preva-
lence study performed in Chad for brucellosis
and Q-fever that using an OH approach in preva-
lence investigations of a zoonosis could decrease
the detection time when sampling humans
and animals in parallel (Schelling et al., 2003).
However, this joint investigation should be justi-
fied with a higher incremental knowledge, and
more importantly, no concessions should be
made in the quality of the methods (Narrod
et al., 2012).
Zinsstag et al. (2007) demonstrated, using
brucellosis, rabies and avian influenza examples,
that interventions against zoonoses become cost
saving when considered from a societal perspec-
tive. An intervention may become highly cost
effective when costs are shared between different
sectors in proportion to their benefits (Roth et al.,
2003). In contrast to developed countries, many
zoonoses are still endemic in many developing
countries, as financial and organizational
resources cannot be focused on the animal
reservoir (Zinsstag et al., 2005).
3.2 Human Tuberculosis: The
International Epidemiological
Situation and Control StrategyAccording to the World Health Organization
(WHO), in 2015, TB caused 1.8 million deaths
worldwide, which puts human TB as a leading
cause of death. In addition, 12% of all TB cases
are co-infected with HIV. The estimated number
of new cases of human TB in the world for 2015
was 10.4 million. The incidence of TB is variable
from one region to another; Southeast Asia and
the Western Pacific accounts for 58% of all TB
cases. Africa has 28% of worldwide TB cases,
but has the most severe burden relative to popu-
lation (WHO, 2016).
On the other hand, Western Europe and
North America showed a low incidence of
human TB compared to the most populous
countries of Asia, where human TB is very prev-
alent (e.g. Bangladesh, India, China, Indonesia,
and Pakistan) (Lawn and Zumla, 2011). In
addition, in some developing countries, an
increase in new TB cases has been observed
within the last 20 years, and this could be
explained, among other reasons, by better data
management and diagnostic rates (WHO,
2016).
In May 2014, the End TB strategy was
established with the goals of reducing the num-
ber of TB deaths by 90% by 2030 (compared to
2015 rates) and reducing the number of new TB
cases by 80% (WHO, 2016).3.3 The Economic and Public Health
Burden of Bovine TuberculosisBovine TB affects the national economy of the
countries where this disease is endemic by
causing a decrease in productivity, condemna-
tion of meat in the abattoirs and an influence on
the international trade of animal products
(Michel et al., 2010). Ongoing bovine TB trans-
mission also has important effects on ecosys-
tems by affecting wildlife (Caron et al., 2003).
Bovine TB is more difficult to eliminate from
wildlife than from cattle. This is currently an
obstacle for the eradication of bovine TB in some
developed countries, for example, badgers in
the UK and Ireland (Mathews et al., 2006;
Gormley and Corner, 2013), the brushtail pos-
sum in New Zealand (Barron et al., 2015), wild
boar (Sus scrofa) in the Iberian Peninsula
(Palmer, 2013) and white-tailed deer (Odocoileus
virginianus) in Michigan, USA (O’Brien et al.,
2009).