HEALTH AND FITNESS
New Rapid Diagnostic Test for Tuberculosis (TB)
The World Health Organization (WHO) endorsed a new diagnostic tool for tuberculosis (TB) in December.
of the best chances of stemming the tide of tuberculosis (TB) epidemic
in low- and middle- income countries is to thwart the transmission cycle
– by diagnosing TB early, and treating it successfully without delay.
The microscope has been around since 1882 as the key standard TB
diagnostic tool, and with low sensitivity (50-60%) and other challenges
in detecting TB in varying conditions and co-morbidities, it is clear
that it is high time we use better, more effective and efficient tools
to accurately detect TB, and neither mis-diagnose nor miss TB diagnosis
in myriad settings.
was a clear thought emerging out of the 'International Symposium on
Tuberculosis Diagnostics: Innovating to make an impact' (ITBS 2010),
organized by the International Centre for Genetic Engineering and
Biotechnology (ICGEB) in New Delhi, India (16-17 December 2010) with
support from the Aeras Global TB Vaccine Foundation, Bill and Melinda
Gates Foundation and Foundation for Innovative New Diagnostics (FIND).
high-income countries have moved on to using better and modern
diagnostic tools, many low- and middle- income countries still rely
principally on sputum smear microscopy.
of the diagnostic tools that the World Health Organization (WHO)
recently endorsed is a fully automated Nucleic Acid Amplification Test (NAAT)
- Xpert ® MTB/RIF - a new and novel rapid test for TB, especially
relevant in high TB burden countries. According to the WHO, the test
could revolutionize TB care and control by providing an accurate
diagnosis for many patients in about 100 minutes, compared to current
tests that can take up to three months to have results. This WHO
endorsement of the NAAT has come after 18 months of rigorous assessment
of its field effectiveness in the early diagnosis of TB, as well as
multidrug-resistant TB (MDR-TB) and TB complicated by HIV infection,
which are more difficult to diagnose.
INCREASE IN DIAGNOSING DRUG-RESISTANT TB POSSIBLE
to the WHO, evidence to date indicates that implementation of this test
could result in a three-fold increase in the diagnosis of patients with
drug-resistant TB and a doubling in the number of HIV-associated TB
cases diagnosed in areas with high rates of TB and HIV.
this new 'while you wait' test incorporates modern DNA technology that
can be used outside of conventional laboratories. It also benefits from
being fully automated and therefore easy and safe to use.
is now calling for the fully automated NAAT to be rolled out under
clearly defined conditions and as part of national plans for TB and MDR-TB
care and control. Policy and operational guidance are also being issued
based on findings from a series of expert reviews and a global
consultation held last week in Geneva. The consultation was attended by
more than a hundred representatives from national programmes,
development aid agencies and international partners.
REDUCTION IN PRICE FOR COUNTRIES MOST AFFECTED BY TB
has been a key concern in the assessment process. Co-developer FIND (the
Foundation for Innovative and New Diagnostics) announced recently it has
negotiated with the manufacturer, Cepheid, a 75% reduction in the price
for countries most affected by TB, compared to the current market price.
Preferential pricing will be granted to 116 low- and middle- income
countries where TB is endemic, with additional reduction in price once
there is significant volume of demand.
has been a strong commitment to remove any obstacles, including
financial barriers, that could prevent the successful roll-out of this
new technology," said Dr Giorgio Roscigno, FIND's Chief Executive
Officer in a WHO communique. "For the first time in TB control, we
are enabling access to state-of-the-art technology simultaneously in
low, middle and high income countries. The technology also allows
testing of other diseases, which should further increase
is also releasing recommendations and guidance for countries to
incorporate this test in their programmes. This includes testing
protocols (or algorithms) to optimize the use and benefits of the new
technology in those persons where it is needed most.
there have been major improvements in TB care and control, tuberculosis
killed an estimated 1.7 million people in 2009 and 9.4 million people
developed active TB last year.