Untreatable TB Strains Alarm
The East African (Nairobi)
NEWS
10 December 2007
Posted to the web 10 December 2007
By Zachary Ochieng
DRUG-RESISTANT STRAINS OF mycobacterium tuberculosis could account for 10 of the 8 million new cases of TB that occur annually, according to a study published in PLoS Medicine, an open access, peer reviewed medical journal.
In the study, systematic surveys have been undertaken in at least 90 countries, with drug-resistant isolates being found in every site, and multidrug-resistant tuberculosis (MDR-TB, resistant to at least isoniazid and rifampin) found in all but eight.
Extensively drug-resistant tuberculosis (XDR-TB) - a disease caused by MDR strains that are also resistant to at least one fluoroquinolone and one or more injectable agents - has been reported in at least 37 countries, with very poor treatment outcomes.
Increasing concern about resistance has redoubled interest in strategies to control drug-resistant TB, especially in settings of high HIV prevalence. There is, therefore, increased urgency for clinical trials that will identify safe and effective regimens for patients who have no treatment options.
MDR-TB can be lethal; five to 20 per cent of HIV-uninfected patients and 66 per cent of HIV-infected patients die during treatment. MDR-TB treatment lasts between 18 and 24 months, and adverse events are common.
The long duration and toxicity of current MDR-TB regimens will impede achievement of the goal of treating nearly 1.6 million MDR-TB patients by 2015, set out in the Global Plan to Stop TB.
In addition, the poor outcomes of current regimens mean that many of those treated will develop chronic, highly resistant forms of TB that have a high mortality rate and can be transmitted to others.
CAROLE D. MITNICK OF HARVARD Medical School, Kenneth G. Castro of the Division of Tuberculosis Elimination of the US Centres for Disease Control and Prevention, Mark Harrington of the Treatment Action Group and Leonard V. Sacks of the US Food and Drug Administration authored the study, titled Randomised Trials to Optimise Treatment of Multidrug-Resistant Tuberculosis.
For the first time in 30 years, several new drug classes that hold promise for MDR-TB treatment are under development; these new agents should be evaluated in parallel for drug-resistant and drug-susceptible TB.
The East African (Nairobi)
NEWS
10 December 2007
Posted to the web 10 December 2007
By Zachary Ochieng
DRUG-RESISTANT STRAINS OF mycobacterium tuberculosis could account for 10 of the 8 million new cases of TB that occur annually, according to a study published in PLoS Medicine, an open access, peer reviewed medical journal.
In the study, systematic surveys have been undertaken in at least 90 countries, with drug-resistant isolates being found in every site, and multidrug-resistant tuberculosis (MDR-TB, resistant to at least isoniazid and rifampin) found in all but eight.
Extensively drug-resistant tuberculosis (XDR-TB) - a disease caused by MDR strains that are also resistant to at least one fluoroquinolone and one or more injectable agents - has been reported in at least 37 countries, with very poor treatment outcomes.
Increasing concern about resistance has redoubled interest in strategies to control drug-resistant TB, especially in settings of high HIV prevalence. There is, therefore, increased urgency for clinical trials that will identify safe and effective regimens for patients who have no treatment options.
MDR-TB can be lethal; five to 20 per cent of HIV-uninfected patients and 66 per cent of HIV-infected patients die during treatment. MDR-TB treatment lasts between 18 and 24 months, and adverse events are common.
The long duration and toxicity of current MDR-TB regimens will impede achievement of the goal of treating nearly 1.6 million MDR-TB patients by 2015, set out in the Global Plan to Stop TB.
In addition, the poor outcomes of current regimens mean that many of those treated will develop chronic, highly resistant forms of TB that have a high mortality rate and can be transmitted to others.
CAROLE D. MITNICK OF HARVARD Medical School, Kenneth G. Castro of the Division of Tuberculosis Elimination of the US Centres for Disease Control and Prevention, Mark Harrington of the Treatment Action Group and Leonard V. Sacks of the US Food and Drug Administration authored the study, titled Randomised Trials to Optimise Treatment of Multidrug-Resistant Tuberculosis.
For the first time in 30 years, several new drug classes that hold promise for MDR-TB treatment are under development; these new agents should be evaluated in parallel for drug-resistant and drug-susceptible TB.
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