March
24 is World TB Day; WHO Report Reveals Record Levels of Multidrug-resistant
and Extensively Drug-resistant Tuberculosis
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SUMMARY:
Levels of multidrug resistant tuberculosis (MDR-TB)
and extensively drug-resistant tuberculosis (XDR-TB)
have reached their highest levels to date, and in some
parts of the world upwards of 25% of the population
is affected, according to a new report from the World
Health Organization (WHO) released in advance of World
TB Day on March 24. In 2008, an estimated 440,000 people
worldwide had MDR-TB, one-third of whom died. While
there is no official XDR-TB estimate, WHO experts think
there may be around 25,000 cases per year, most of them
fatal. For more information on World TB Day, see http://www.stoptb.org/events/world_tb_day/2010. |
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Below
is the text of a WHO press release announcing the report and summarizing
some of its key findings.
[The
full report is available online]
Drug-resistant
Tuberculosis Now at Record Levels
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Tuberculosis
bacillus
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Geveva/Washington,
DC -- March 18, 2010 -- In some areas of the world, one in four
people with tuberculosis (TB) becomes
ill with a form of the disease that can no longer be treated with
standard drugs regimens, a World Health Organization (WHO) report
says.
For example, 28% of all people newly diagnosed with TB in one
region of northwestern Russia had the multidrug-resistant form
of the disease (MDR-TB) in 2008. This is the highest level ever
reported to WHO. Previously, the highest recorded level was 22%
in Baku City, Azerbaijan, in 2007.
In
the new WHO's Multidrug and Extensively Drug-Resistant Tuberculosis:
2010 Global Report on Surveillance and Response, it is estimated
that 440,000 people had MDR-TB worldwide in 2008 and that a third
of them died. In sheer numbers, Asia bears the brunt of the epidemic.
Almost 50% of MDR-TB cases worldwide are estimated to occur in
China and India. In Africa, estimates show 69,000 cases emerged,
the vast majority of which went undiagnosed.
Encouraging signs
Tuberculosis
programs face tremendous challenges in reducing MDR-TB rates.
But there are encouraging signs that even in the presence of severe
epidemics, governments and partners can turn around MDR-TB by
strengthening efforts to control the disease and implementing
WHO recommendations.
Two regions in the Russian Federation, Orel and Tomsk, have achieved
a remarkable decline in MDR-TB in about five years. These regions
join two countries, Estonia and Latvia, which have reversed rising
high rates of MDR-TB, ultimately achieving a decline. The United
States of America and China, Hong Kong Special Administrative
Region (SAR), have achieved sustained successes in controlling
MDR-TB.
Progress
remains slow in most other countries. Worldwide, of those patients
receiving treatment, 60% were reported as cured. However, only
an estimated 7% of all MDR-TB patients are diagnosed. This points
to the urgent need for improvements in laboratory facilities,
access to rapid diagnosis and treatment with more effective drugs
and regimens shorter than the current two years.
WHO is engaged in a five-year project to strengthen TB laboratories
with rapid tests in nearly 30 countries. This will ensure more
people benefit early from life-saving treatments. It is also working
closely with the Global Fund to Fight AIDS, Tuberculosis and Malaria
and the international community on increasing access to treatment.
Multidrug-resistant
TB (MDR-TB) is caused by bacteria that are resistant to
at least isoniazid and rifampicin, the most effective anti-TB
drugs. MDR-TB results from either primary infection with resistant
bacteria or may develop in the course of a patient's treatment.
Extensively drug-resistant TB (XDR-TB) is a form of TB
caused by bacteria that are resistant to isoniazid and rifampicin
(i.e. MDR-TB) as well as any fluoroquinolone and any of the
second-line anti-TB injectable drugs (amikacin, kanamycin or
capreomycin).
These forms of TB do not respond to the standard six-month treatment
with first-line anti-TB drugs and can take up to two years or
more to treat with drugs that are less potent, more toxic and
much more expensive, from 50 to 200 times higher. While a course
of standard TB drugs cost approximately US$ 20, MDR-TB drugs
can cost up to US$ 5,000, and XDR-TB treatment is far more expensive.
In 2008, there were an estimated 9.4 million new TB cases, and
1.8 million TB deaths. 440,000 MDR-TB cases are estimated to
have emerged in the same year with 150,000 MDR-TB deaths. No
official estimates have been made on the number of XDR-TB cases,
but there may be around 25,000 a year with most cases fatal.
Since XDR-TB was first defined in 2006, a total of 58 countries
have reported at least one case of XDR-TB.
In
27 high burden countries (i.e. countries estimated to have had
at least 4000 MDR-TB cases arising annually and/or at least 10%
of newly registered TB cases with MDR-TB), 1.3 million M/XDR-TB
cases will need to be treated between 2010 and 2015 at a cost
of US$ 16 billion over six years, rising from US$ 1.3 billion
in 2010 to US$ 4.4 billion in 2015. Planned budget for 2010 are
far below these figures, amounting to less than US$ 0.5 billion
for all 27 countries. Actual funding available for 2010 was US$
280 million. Funding needed for MDR-TB control in 2015 will be
16 times higher than what is currently available in 2010.
Strengthening
laboratories
There
is an urgent need to expand and accelerate in countries access
to new, rapid technologies that can diagnose MDR-TB in two days
rather than traditional methods which can take up to four months.
EXPAND TB is a five-year project targeting 27 countries, launched
in 2008 and implemented by WHO, the Foundation for Innovative
New Diagnostics (FIND), the Stop TB Partnership's Global Drug
Facility (GDF) and the Global Laboratory Initiative (GLI) with
financial support from UNITAID. So far it has carried out a wide
range of activities in 12 countries, including upgrading of infrastructure
and training of staff. Technology transfer has started in countries,
paving the way for more patients to be diagnosed accurately and
rapidly enrolled on treatment. These upgrades should lead to eventual
routine surveillance of drug resistance in affected countries.
Countries
and case studies
Six
countries are featured throughout the report in special focus
sections. Bangladesh (one of the very few developing countries
in which continuous surveillance among previously treated TB cases
is being carried out in selected areas); China (first nationwide
drug resistance survey conducted); Ethiopia (one of the first
countries to introduce rapid molecular laboratory tests); Nepal
and Romania (successful treatments of MDR-TB through Green Light
Committee Initiative programmes); South Africa (policy changes
for improving the management and care of M/XDR-TB).
In
Africa, there is a low percentage of MDR-TB reported among new
TB cases compared with that in regions such as Eastern Europe
and Central Asia, due in part to the limited laboratory capacity
to conduct drug resistance surveys. Latest estimates of WHO put
the number of MDR-TB cases emerging in 2008 in Africa at 69,000.
Previous reports found high levels of mortality among people living
with HIV and infected with MDR-TB and XDR-TB. In KwaZulu Natal
in South Africa, an outbreak of XDR-TB killed 52 out of 53 people
within three weeks, most of whom were HIV positive.
Risk
factors: HIV and MDR-TB
Studies
show that TB patients co-infected with HIV in three Eastern European
countries (Estonia, Latvia, and the Republic of Moldova) were
at a higher risk of having MDR-TB compared to TB patients without
HIV infection. Similar findings have been made in studies from
Lithuania, Ukraine and Mozambique.
The report highlights several reasons why drug-resistant TB may
be associated with HIV, particularly in some Eastern European
countries. However, more research is needed to determine whether
there is an overlap between the MDR-TB and HIV epidemics worldwide.
Reporting
on MDR-TB globally
This
report presents drug resistance data from 114 countries and updated
information from 35 of them. Despite the growing understanding
of the magnitude and trends in drug-resistant TB, major gaps remain
in geographical areas covered. Since 1994, only 59% of all countries
globally have been able to collect high quality representative
data on drug resistance. There is an urgent need to obtain information,
particularly from Africa and those high MDR-TB burden countries
where data have never been reported: Bangladesh, Belarus, Kyrgyzstan,
Pakistan and Nigeria. Moreover, countries need to expand the scope
of their surveys to cover entire populations, repeat surveys are
needed to better understand trends in drug resistance and countries
need to move towards adopting systematic continuous surveillance.
3/23/10
Reference
World
Health Organization. Multidrug and extensively drug-resistant
TB (M/XDR-TB). 2010 Global Report on Surveillance and Response
(WHO/HTM/TB/2010.3). 2010.
Source
World
Health Organization. Drug-resistant tuberculosis now at record
levels. Press release. March 18, 2010.
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