- WASHINGTON -- International
incidents have focused recent attention on deadly forms of drug-resistant
tuberculosis (TB), and the World Health Organization (WHO) and the Stop
TB Partnership are launching a two-year plan to help patients and communities
most at risk.
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- The Global MDR-TB and XDR-TB Response Plan 2007-2008
set out measures needed over the next two years to prevent, treat and
control extensively drug-resistant TB (XDR-TB) and multidrug- resistant
TB (MDR-TB). The plan lays out steps to give access to drugs and diagnostic
tests to all MDR- and XDR-TB patients by 2015, potentially saving up to
1.2 million lives.
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- The Stop TB Partnership, formed in 2000 to eliminate
TB as a public health problem, is a network of more than 500 international
organizations, countries, public-sector and private donors, and nongovernmental
and governmental organizations.
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- The plan emphasizes an urgent need to boost basic TB
control and to target investment in strengthening programs for treating
drug- resistant TB, building capacity in diagnostic laboratories, expanding
infection control and surveillance, and supporting research in diagnostics,
drugs and vaccines.
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- "The persistence of the TB epidemic underscores
the importance of continuing fundamental research," said Dr. Anthony
Fauci, director of the U.S. National Institute of Allergy and Infectious
Diseases, (the lead agency of the US National Institutes of Health for
TB research) in a recent statement, "to better understand how [MDR-
TB] interacts with the host and to translate these findings into new health
care interventions to improve the diagnosis, treatment and prevention
of TB infection and disease."
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- TB microbes spread from person to person through the
air. Globally, nearly 9 million people get TB each year, and 1.6 million
die as a result.One-third of the world population is infected with latent
(inactive) TB. The disease usually does not become active unless something
reduces a person's immunity -- a disease like AIDS, advancing age or some
medical conditions.
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- TB is treated with a six- to nine-month course of "first-
line" (most effective) drugs. If patients do not complete the drug
course or are not treated properly, they can develop MDR-TB, which is
resistant to at least two of the best anti-TB drugs, isoniazid and rifampicin.
Those with MDR-TB must be treated with more expensive, less effective
second-line drugs for 18 to 24 months.
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- If they do not complete this course or are treated with
the wrong drugs, they can develop XDR-TB, a relatively rare type of MDR-TB
that is resistant to first- and second-line drugs. There could be 50,000
cases of XDR-TB worldwide.
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- Worldwide attention focused on XDR-TB in March 2006,
when researchers reported a cluster of untreatable XDR-TB cases in South
Africa amongst HIV+ patients. All but one of the first 54 identified
patients died within 25 days after samples were taken for drug-resistance
tests, the 54th patient died within 30 days.
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- In May, scientists at the U.S. Centers for Disease Control
and Prevention (CDC) diagnosed an international air traveler from the
United States with XDR-TB. (See related article.) After Andrew Speaker
-- a 31-year-old lawyer from Atlanta -- returned to the United States
and was served with a federal order of isolation, he traveled to the National
Jewish Medical and Research Center in Colorado, a leader in treating lung
diseases.
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- There, on July 3, officials from CDC and National Jewish
announced that tests from National Jewish and a second test from CDC showed
that Speaker actually had (the still curable) MDR-TB."There's not
a lot of difference between XDR- and MDR-TB in the sense that the public
health response is the same," said Dr. Charles Daley, head of the
Infectious Disease Division at National Jewish, during a July 3 press
briefing.
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- "It makes a big difference to me, as a clinician,
however," he added, "because I can pick another couple of drugs
up and add them to the treatment regimen and improve the chance of cure."
- The Difference In Lab Results In Speaker Case Are Puzzling:
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- Even though CDC and National Jewish are both TB reference
laboratories (regional or national resources with specific technical
capabilities), and CDC is an international reference lab, CDC officials
are not yet sure why their own initial lab results indicated XDR-TB in
Mr Speaker. "Any time there is a concern or conflict with a test
result," said Dr. Mitchell Cohen, director of CDC's Coordinating
Center for Infectious Diseases, "we automatically review those results
and see whether there are clear explanations as for the differences."
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- "We need to develop a gold-standard test":
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- A significant problem, Cohen added, is "not having
the types of diagnostic tests we truly need to be able to address the
challenge from TB. Different or discordant test results in different
laboratories are an important issue. If we could, working together, develop
a gold-standard test that could give us a definite answer, that would
be a tremendous step in the right direction."
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- TB test results of all the passengers and crew who had
traveled on the trans-Atlantic flights with Speaker will be completed
over the next few weeks.
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- http://usinfo.state.gov/xarchives/display.html?p=washfile-
english&y=2007&m=July&x=20070706113030lcnirellep0.1079981
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