Info Service on Health Issues (March 07/04)
Drug-resistant TB treatment barely succeeds
as WHO released a report which said that the global TB epidemic had
levelled off since 1993, Medecins Sans Frontieres released statistics
showing that even under optimised conditions, treatment will succeed
in barely half of patients with multi-drug resistant TB. Some patients
go on to develop extensively drug resistant TB. The article below reports
on both views.
is reproduced with permission from South-North Development Monitor (SUNS)
#6217, 23 March 2007.
Health: Treating drug-resistant
TB, a losing battle?
By Kanaga Raja, Geneva, 22 March 2007
Multi-drug resistant and
extensively drug-resistant tuberculosis are the tip of an iceberg of
failing strategies to curb tuberculosis, and the World Health Organization
needs to take the lead in developing new strategies against the disease,
the international medical humanitarian organization Medecins Sans Frontieres
(MSF) warned Thursday.
This grim warning from MSF comes even as the World Health Organization
released a report on Thursday in which it maintained that the global
tuberculosis (TB) epidemic had leveled off for the first time since
the WHO declared the disease a public health emergency in 1993.
The Global Tuberculosis Control Report 2007 of the WHO said that the
percentage of the world's population struck by TB peaked in 2004 and
then held steady in 2005.
The WHO however acknowledged that the spread of extensively drug-resistant
TB (XDR-TB) poses a serious threat to progress and could reverse recent
"We have a clear plan on how to control XDR-TB, but countries are
moving far too slowly on implementing this plan. Funding is an issue
as well - it will take an additional $650 million globally to implement
control of both XDR-TB and multi-drug-resistant TB (MDR-TB) in 2007
alone," said Dr Mario Raviglione, Director of the WHO Stop TB Department.
"Beyond that, because of the threat of XDR-TB, research to identify
new diagnostics, drugs and vaccines is more vital than ever," the
WHO official added.
MSF released statistics on Thursday showing that even under optimised
conditions, treatment will succeed in barely more than half of patients
with multi-drug resistant tuberculosis (MDR-TB).
As insufficient research and development on new drugs and diagnostics
has left health staff without the right tools to treat the disease,
some patients will go on to develop extensively drug-resistant tuberculosis
(XDR-TB) regardless of the quality of care they are offered. The situation
is particularly alarming when treating people co-infected with TB and
HIV, said MSF.
"When resistance emerges to the major TB drugs, we're forced to
go back to using older less effective ones," said Dr. Jessica Adam,
a doctor in MSF's programme in Uzbekistan. "This means a much longer,
much more expensive treatment course that can cost up to $15,000, and
especially relying on drugs that are toxic: the side effects are simply
MSF said that since 1999, it has invested considerable resources, and
provided rigorous support to treat 570 patients with MDR-TB in Armenia,
Abkhazia, Georgia, Cambodia, Kenya, Thailand, Uganda, and Uzbekistan.
Despite these efforts, only 55% of these patients completed the 18-24
month course of treatment. The remaining 45% died, did not improve on
treatment, or defaulted because of side effects, isolation, and other
difficulties in tolerating the treatment.
Diagnosing MDR-TB is also extremely difficult, said MSF. Most resource-poor
settings do not have access to the necessary sophisticated equipment.
But even in the best of settings that do, it can take up to eight weeks
to get a result. In patients co-infected with HIV who are already sick,
such delays can mean the difference between life and death.
"In places where we see a lot of HIV/AIDS, the risk of MDR-TB spreading
like wildfire is a terrifying, but all too likely prospect," said
Dr. Liesbet Ohler from MSF's programme in Mathare, a slum near Nairobi.
"Treating MDR-TB and HIV simultaneously is incredibly frustrating
because of drug interactions and the potential for many strong side
effects, let alone the number of pills patients have to take everyday.
With the tools we have today, we're fighting a losing battle."
Last year's XDR epidemic in South Africa sparked international concern
about the extent of the crisis and the urgency of finding solutions,
MSF said, stressing that concrete actions need to be taken now. The
WHO needs to take the lead to develop new strategies against the disease.
Despite the urgency of the situation, MSF said that current research
efforts are not keeping pace with the need for better tests, drugs and
vaccines. An analysis conducted by MSF of the TB research and development
pipeline found that none of the compounds under development today will
be able to deliver the drastically shorter treatment that is needed
to curb the disease.
Similarly, the diagnostics under development will not be simple enough
to use in resource-limited settings and will not reliably detect the
disease. There is a critical funding gap for research and development
for TB with around $900 million needed annually but only $206 million
being invested, said MSF.
"MDR-TB, and now XDR-TB are the tip of an iceberg of failing strategies
to curb TB. We desperately need new tools and we need them now - we
cannot just sit and wait," said Dr. Tido von Schoen-Angerer, Director
of MSF's Campaign for Access to Essential Medicines.
"There is no quick ready-made solution, but that is not an excuse
not to act. One important step is to have all TB drugs in development
tested in trials with MDR patients: this would be a quicker way to see
whether new compounds are efficacious for patients with regular TB and
give those with MDR a chance for a better treatment. At the moment,
only one company has stated that it is planning to conduct an MDR trial
while others sit on the fence. WHO needs to ensure that these trials
will happen," he added.
Meanwhile, according to the WHO Global Tuberculosis Control Report,
the global tuberculosis epidemic is leveling off, with the percentage
of the world's population struck by TB peaking in 2004 and holding steady
The WHO said that although the rate at which people developed TB in
2005 was level or even declined slightly compared to 2004, the actual
number of TB cases continued to rise slowly. The reason for this difference
is that world population is expanding.
The pace at which new TB cases developed in 2005, however, was slightly
lower than global population growth. The number of cases in 2005 was
8,787,000, up from 8,718 000 in 2004. An estimated 1.6 million people
died of the disease in 2005, 195,000 of them people living with HIV.
The WHO said that more than 90 million TB patients were reported to
the organization between 1980 and 2005.
The WHO report noted that facilities to diagnose and treat MDR-TB, including
XDR-TB are not widely available yet, and that the scale of the XDR-TB
problem globally is not yet known.
The WHO also highlighted an overall funding gap for TB control. Although
funds for TB control have risen substantially since 2002, reaching $2
billion, an additional $1.1 billion will be needed to meet the 2007
funding requirements set by the Global Plan to Stop TB (2006-2015).
A total of $56 billion - half of which should be funded by endemic countries
and the other half by donors - is needed for the 10-year plan, but current
funding commitments indicate a gap of at least $31 billion.
The WHO report also found that the WHO Regions of the Americas, South-East
Asia and the Western Pacific are now on track to meet their 2015 Global
Plan Targets (to halve 1990 TB case numbers and deaths from the disease
by 2015); while the African, Eastern Mediterranean and European regions
The WHO said that its 2005 targets of 70% case detection and 85% cure
were narrowly missed globally: case detection was 60% and treatment
success was 84%.
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