Bovine tuberculosis

Economics of Bovine Tuberculosis: A One Health Issue 37

population per year) in Africa, based on infor-
mation from African countries for which data is
available. However, no data are available for
quantifying the number of human TB patients
infected with M. bovis in many developing coun-
tries in Africa and elsewhere. This could be due
to a weak communication between human and
veterinary health systems, which calls for an OH
approach. In addition to a lack of awareness of a
potential high burden of M. bovis among
humans, in settings where bovine TB has a high
prevalence among cattle and several risk factors
for transmission of bovine TB to humans are
present (e.g. consumption of unpasteurized
milk, close contact between humans and cattle),
the burden of M. bovis should be urgently
considered.
Morocco is a developing country where
the prevalence of bovine TB among cattle is
18% (FAO, 2011), and 40% of the population
live in rural areas (La Banque Mondiale, 2014)
in close contact with cattle. The burden of
M. bovis among human TB cases should be
investigated, as the risk factors for zoonotic TB
transmission from animals to humans are pres-
ent. In this context, an OH approach should
be introduced where the human health and
veterinary efforts are integrated in order to
investigate the real burden of M. bovis in
humans in such settings, but such collaboration
needs an improved communication between
both sectors.
A recent transmission model (Fig. 3.1) of
bovine TB in Morocco showed that the disease
could be controlled within 20 years, if 60%

of Moroccan cattle were tested annually and

infected animals were slaughtered. This 20-year

campaign is projected to cost ?1.53 billion

( Abakar et al., 2017). Further analyses on the

profitability and cost effectiveness are ongoing.

The transmission model used to estimate the

cost of bovine TB elimination in Morocco con-

sidered three categories for cattle (susceptible,

exposed with latent TB, and infected with active

TB). The human population was divided into

four categories (susceptible, exposed with latent

zoonotic TB, infected with active TB, and recov-

ered from TB). In order to represent the human

burden of bovine TB, a transmission from

infected cattle to exposed humans was consid-

ered in the model (Abakar et al., 2017).

3.8 Towards the Control and

Elimination of Bovine Tuberculosis in

Developing Countries

In Japan, the tuberculin skin test was introduced

in 1948, and the test-and-slaughter strategy

was applied, followed by an annual examina-

tion. Consequently, bovine TB prevalence

dropped quickly and the disease was nearly

eliminated from cattle in Japan (Shimao, 2010).

Several developed countries were able to elimi-

nate bovine TB using the test-and-slaughter

strategy, and the success of this strategy was

supported by the absence of a wildlife reservoir

(Wedlock et al., 2002). Switzerland is one of the

success stories of bovine TB eradication, where

Fig. 3.1. Schematic diagram of the bovine TB cattle–human transmission model for Morocco (Abakar
et al., 2017).

b

Cattle

C

mC

SC bC

mC

EC aC

mC

IC

b

Humans

H

mH

SH bH

mH

EH aH

dH

mH

IH YH

mH

RH