Key facts on TUBERCULOSIS......

Tuberculosis (TB) is one of the top 10 causes
of death worldwide.
In 2016, 10.4 million people fell ill with TB, and
1.7 million died from the disease (including
0.4 million among people with HIV). Over 95%
of TB deaths occur in low- and middle-income
countries.
Seven countries account for 64% of the total,
with India leading the count, followed by
Indonesia, China, Philippines, Pakistan, Nigeria,
and South Africa.
In 2016, an estimated 1 million children
became ill with TB and 250 000 children died
of TB (including children with HIV associated
TB).
TB is a leading killer of HIV-positive people: in
2016, 40% of HIV deaths were due to TB.
Multidrug-resistant TB (MDR-TB) remains a
public health crisis and a health security threat.
WHO estimates that there were 600 000 new
cases with resistance to rifampicin – the most
effective first-line drug, of which 490 000 had
MDR-TB. Globally, TB incidence is falling at
about 2% per year. This needs to accelerate to
a 4–5% annual decline to reach the 2020
milestones of the End TB Strategy.
An estimated 53 million lives were saved
through TB diagnosis and treatment between
2000 and 2016.
Ending the TB epidemic by 2030 is among the
health targets of the Sustainable Development
Goals.
Tuberculosis (TB) is caused by bacteria
(Mycobacterium tuberculosis) that most often
affect the lungs. Tuberculosis is curable and
preventable.
TB is spread from person to person through the
air. When people with lung TB cough, sneeze or
spit, they propel the TB germs into the air. A
person needs to inhale only a few of these germs
to become infected.
About one-quarter of the world's population has
latent TB, which means people have been infected
by TB bacteria but are not (yet) ill with the disease
and cannot transmit the disease.
People infected with TB bacteria have a 5–15%
lifetime risk of falling ill with TB. However, persons
with compromised immune systems, such as
people living with HIV, malnutrition or diabetes, or
people who use tobacco, have a much higher risk
of falling ill.
When a person develops active TB disease, the
symptoms (such as cough, fever, night sweats, or
weight loss) may be mild for many months. This
can lead to delays in seeking care, and results in
transmission of the bacteria to others. People
with active TB can infect 10–15 other people
through close contact over the course of a year.
Without proper treatment, 45% of HIV-negative
people with TB on average and nearly all HIV-
positive people with TB will die.
Who is most at risk?
Tuberculosis mostly affects adults in their most
productive years. However, all age groups are at
risk. Over 95% of cases and deaths are in
developing countries.
People who are infected with HIV are 20 to 30
times more likely to develop active TB (see TB and
HIV section below). The risk of active TB is also
greater in persons suffering from other conditions
that impair the immune system.
One million children (0–14 years of age) fell ill
with TB, and 250 000 children (including children
with HIV associated TB) died from the disease in
2016.
Tobacco use greatly increases the risk of TB
disease and death. 8% of TB cases worldwide are
attributable to smoking.
Global impact of TB
TB occurs in every part of the world. In 2016, the
largest number of new TB cases occurred in Asia,
with 45% of new cases, followed by Africa, with
25% of new cases.
In 2016, 87% of new TB cases occurred in the 30
high TB burden countries. Seven countries
accounted for 64% of the new TB cases: India,
Indonesia, China, Philippines, Pakistan, Nigeria,
and South Africa. Global progress depends on
advances in TB prevention and care in these
countries.
Symptoms and diagnosis
Common symptoms of active lung TB are cough
with sputum and blood at times, chest pains,
weakness, weight loss, fever and night sweats.
Many countries still rely on a long-used method
called sputum smear microscopy to diagnose TB.
Trained laboratory technicians look at sputum
samples under a microscope to see if TB bacteria
are present. Microscopy detects only half the
number of TB cases and cannot detect drug-
resistance.
The use of the rapid test Xpert MTB/RIF® has
expanded substantially since 2010, when WHO
first recommended its use. The test
simultaneously detects TB and resistance to
rifampicin, the most important TB medicine.
Diagnosis can be made within 2 hours and the
test is now recommended by WHO as the initial
diagnostic test in all persons with signs and
symptoms of TB. More than 100 countries are
already using the test and 6.9 million cartridges
were procured globally in 2016.
Diagnosing multi-drug resistant and extensively
drug-resistant TB (see Multidrug-resistant TB
section below) as well as HIV-associated TB can
be complex and expensive. In 2016, 4 new
diagnostic tests were recommended by WHO – a
rapid molecular test to detect TB at peripheral
health centres where Xpert MTB/RIF cannot be
used, and 3 tests to detect resistance to first- and
second-line TB medicines.
Tuberculosis is particularly difficult to diagnose in
children and as yet only the Xpert MTB/RIF assay
is generally available to assist with the diagnosis
of paediatric TB.
Treatment
TB is a treatable and curable disease. Active, drug-
susceptible TB disease is treated with a standard
6 month course of 4 antimicrobial drugs that are
provided with information, supervision and
support to the patient by a health worker or
trained volunteer. Without such support, treatment
adherence can be difficult and the disease can
spread. The vast majority of TB cases can be
cured when medicines are provided and taken
properly.
Between 2000 and 2016, an estimated 53 million
lives were saved through TB diagnosis and
treatment.
TB and HIV
People living with HIV are 20 to 30 times more
likely to develop active TB disease than people
without HIV.
HIV and TB form a lethal combination, each
speeding the other's progress. In 2016 about 0.4
million people died of HIV-associated TB. About
40% of deaths among HIV-positive people were
due to TB in 2016. In 2016, there were an
estimated 1.4 million new cases of TB amongst
people who were HIV-positive, 74% of whom were
living in Africa.
WHO recommends a 12-component approach of
collaborative TB-HIV activities, including actions
for prevention and treatment of infection and
disease, to reduce deaths.
Multidrug-resistant TB
Anti-TB medicines have been used for decades
and strains that are resistant to 1 or more of the
medicines have been documented in every country
surveyed. Drug resistance emerges when anti-TB
medicines are used inappropriately, through
incorrect prescription by health care providers,
poor quality drugs, and patients stopping
treatment prematurely.
Multidrug-resistant tuberculosis (MDR-TB) is a
form of TB caused by bacteria that do not respond
to isoniazid and rifampicin, the 2 most powerful,
first-line anti-TB drugs. MDR-TB is treatable and
curable by using second-line drugs. However,
second-line treatment options are limited and
require extensive chemotherapy (up to 2 years of
treatment) with medicines that are expensive and
toxic.
In some cases, more severe drug resistance can
develop. Extensively drug-resistant TB (XDR-TB) is
a more serious form of MDR-TB caused by
bacteria that do not respond to the most effective
second-line anti-TB drugs, often leaving patients
without any further treatment options.
In 2016, MDR-TB remains a public health crisis
and a health security threat. WHO estimates that
there were 600 000 new cases with resistance to
rifampicin – the most effective first-line drug – of
which 490 000 had MDR-TB. The MDR-TB burden
largely falls on 3 countries – India, China and the
Russian Federation – which together account for
nearly half of the global cases. About 6.2% of
MDR-TB cases had XDR-TB in 2016.
Worldwide, only 54% of MDR-TB patients and 30%
of XDR-TB are currently successfully treated. In
2016, WHO approved the use of a short,
standardised regimen for MDR-TB patients who
do not have strains that are resistant to second-
line TB medicines. This regimen takes 9–12
months and is much less expensive than the
conventional treatment for MDR-TB, which can
take up to 2 years. Patients with XDR-TB or
resistance to second-line anti-TB drugs cannot
use this regimen, however, and need to be put on
longer MDR-TB regimens to which 1 of the new
drugs (bedquiline and delamanid) may be added.
WHO also approved in 2016 a rapid diagnostic
test to quickly identify these patients. More than
35 countries in Africa and Asia have started using
shorter MDR-TB regimens. By June 2017, 89
countries had introduced bedaquiline and 54
countries had introduced delamanid, in an effort to
improve the effectiveness of MDR-TB treatment
regimens.
WHO response
WHO pursues 6 core functions in addressing TB:
1. Providing global leadership on matters critical
to TB.
2. Developing evidence-based policies,
strategies and standards for TB prevention,
care and control, and monitoring their
implementation.
3. Providing technical support to Member
States, catalyzing change, and building
sustainable capacity.
4. Monitoring the global TB situation, and
measuring progress in TB care, control, and
financing.
5. Shaping the TB research agenda and
stimulating the production, translation and
dissemination of valuable knowledge.
6. Facilitating and engaging in partnerships for
TB action.
The WHO End TB Strategy , adopted by the World
Health Assembly in May 2014, is a blueprint for
countries to end the TB epidemic by driving down
TB deaths, incidence and eliminating catastrophic
costs. It outlines global impact targets to reduce
TB deaths by 90%, to cut new cases by 80%
between 2015 and 2030, and to ensure that no
family is burdened with catastrophic costs due to
TB.
Ending the TB epidemic by 2030 is among the
health targets of the newly adopted Sustainable
Development Goals. WHO has gone one step
further and set a 2035 target of 95% reduction in
deaths and a 90% decline in TB incidence –
similar to current levels in low TB incidence
countries today.
The Strategy outlines three strategic pillars that
need to be put in place to effectively end the
epidemic:
Pillar 1: integrated patient-centred care and
prevention
Pillar 2: bold policies and supportive systems
Pillar 3: intensified research and innovation
The success of the Strategy will depend on
countries respecting the following 4 key principles
as they implement the interventions outlined in
each pillar:
government stewardship and accountability,
with monitoring and evaluation
strong coalition with civil society organizations
and communities
protection and promotion of human rights,
ethics and equity
adaptation of the strategy and targets at
country level, with global collaboration.