Rapid Spread of Deadly New TB Strains Expose New Drug Need
Pastor Dale Morgan
Rapid Spread of Deadly New TB Strains Expose New Drug Need*
By ANGELA DOLAND
The Associated Press
Monday, October 30, 2006; 3:47 PM
PARIS -- A deadly drug-resistant new strain of tuberculosis on the rise
this year has forced scientists to confront a new problem: old drugs and
a more than century-old TB test that takes weeks to get laboratory
confirmation.
Scientists, doctors and public health specialists met in Paris on Monday
to discuss the urgent need for better tests, new drugs and a broadly
effective vaccine. Tuberculosis will also come up later this week at the
annual Union World Conference on Lung Health, also in Paris.
The TB drugs prescribed today are more than 40 years old, and they
require patients to undergo a six- to nine-month treatment regimen.
Tuberculosis, a respiratory illness spread by coughing and sneezing, is
the world's deadliest curable infectious disease. The World Health
Organization estimates that 1.7 million people die from TB every year.
The U.S. Centers for Disease Control and Prevention and the World Health
Organization surveyed laboratories on six continents from 2000 to 2004
and found that one in 50 TB cases around the world is resistant not only
to the usual first-choice TB treatments, but also to many medications
that represent the last line of defense. That classifies the disease as
extensively drug resistant TB, or XDR.
XDR-TB is virtually incurable with existing antibiotics. In the South
African province of KwaZulu-Natal, where 53 patients were found to have
the disease recently, all but one of them died within a month, health
experts say. For XDR-TB patients also infected with HIV/AIDS, disease
progression has been disturbingly quick, with a mortality rate
approaching 100 percent. With high HIV/AIDS prevalence rates across
Africa, treating XDR-TB will prove tremendously challenging.
"The problem of extensively resistant tuberculosis is a very rude
wake-up call," Kenneth G. Castro, director of the TB elimination program
at the CDC, said at Monday's conference, hosted by the Global Alliance
for TB Drug Development.
"We don't know how frequently this occurs in different parts of the
world," he said, urging rapid surveys to find out.
For more than a decade, health officials have worried about
multidrug-resistant TB, which can withstand the mainline antibiotics
isoniazid and rifampin.
There are probably not enough new drugs in the works, said the French
aid group Medecins Sans Frontieres, known in English as Doctors Without
Borders.
The group released an analysis Monday suggesting that none of the drugs
currently in development will bring dramatic and rapid improvement to
fighting TB, and it urged more financial support for the TB alliance and
other efforts.
The group expressed concern that many drugs in development are similar
to existing compounds, which may mean they are less effective in
fighting resistant strains.
The number of TB drugs being developed is still "small compared to the
drug pipelines for diseases of major concern to wealthy countries, such
as cancer or cardiovascular disease," the analysis said.
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