FIRS The Global Impact of Respiratory Disease – Second Edition | Page 21

Tuberculosis
Scope of the disease
In 2015, there were 10.4 million new cases of
TB. Of these, 1 million were children, which
is likely to be an underestimate because the
diagnosis of paediatric TB is challenging.
In 2015, there were an estimated 480,000
new cases of multidrug-resistant TB, and
an additional 100,000 people developed
rifampicin-resistant disease [8]. Among new
cases of TB, 11% of people also had co-
infection with HIV. In 2015, TB killed 1.4
million people, making it the greatest single
infectious agent cause of death and a leading
cause of overall deaths in the world. When
combined with HIV, it killed another 400,000
people [8]. Twenty countries accounted for
84% of the cases of TB [8].
Only recently has TB in children begun to
receive the attention it deserves. Paediatric TB
has been largely ignored because, in general,
children are thought to not spread the disease.
Moreover, TB is diffi cult to diagnose in young
children because they usually do not produce
sputum. The high susceptibility of infants
and young children to extrapulmonary a nd
disseminated disease adds to the complexity
of diagnosis. Consequently, diagnostic
approaches for children have lagged.
Likewise, antituberculous drug formulations
have not been developed for paediatric use
until recently.
The incidence of TB is falling at a rate of about
1.5% per year, which is insuffi cient to end
tuberculosis by the WHO’s stated goal of 2035.
Deaths due to TB decreased 17% between
2005 and 2015, and age-standardised TB
death rates decreased 34% [1]. The treatment
success rate is 83% for drug-sensitive TB,
52% for multidrug-resistant TB and 28% for
extensively drug-resistant TB [8].
The global case-fatality rate remains high at
17%, but varies from less than 5% to more
than 20% [8]. The cost of treating multiple
drug-resistant TB is many times the cost of
treating drug-sensitive disease and strains TB
control programme budgets [33, 34]. About
910,000 persons living with HIV and 87,000
children aged under 5 years began treatment
of latent TB in 2015, but this is only 7% of the
eligible children [8].
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Forum of International Respiratory Societies