Wednesday, September 06, 2006

Party Like There's No Tomorrow

The World Health Organization is reporting that a virulent type of tuberculosis is on the rise which is resistant to our second tier of antibiotics.

Tuberculosis causes about 1.7 million deaths a year worldwide, but researchers are worried about the emergence of strains that are resistant to drugs.

Multidrug-resistant TB is already a concern because at least two of the main first-line drugs won't work against the strain.

Now, extensive drug-resistant TB or XDR-TB is emerging, in which the bacteria resist not only front-line drugs, but also three of the more than six classes of second-line drugs. While more potent, these medications have more serious side-effects, are more expensive and may need to be taken for as long as two years.

On average, about one per cent of all strains are drug-resistant, and of those, between five and 15 per cent are extensively drug-resistant, said Dr. Anne Fanning, a professor emeritus at the University of Alberta's faculty of medicine....

The XDR-TB strains were found most frequently in the former Soviet Union and Asia. Cases are also on the rise in Africa.

"Given the underlying HIV epidemic, drug-resistant TB could have a severe impact on mortality in Africa and requires urgent preventative action," WHO said in a statement.|CBC|


According to this Tuberculosis fact sheet published by WHO, TB becomes antibiotic resistant when people stop taking the medications before the course of treatment is complete.

Drug-resistant TB is caused by inconsistent or partial treatment, when patients do not take all their medicines regularly for the required period because they start to feel better, because doctors and health workers prescribe the wrong treatment regimens, or because the drug supply is unreliable. A particularly dangerous form of drug-resistant TB is multidrug-resistant TB (MDR-TB), which is defined as the disease caused by TB bacilli resistant to at least isoniazid and rifampicin, the two most powerful anti-TB drugs. Rates of MDR-TB are high in some countries, especially in the former Soviet Union, and threaten TB control efforts.

While drug-resistant TB is generally treatable, it requires extensive chemotherapy (up to two years of treatment) that is often prohibitively expensive (often more than 100 times more expensive than treatment of drug-susceptible TB), and is also more toxic to patients. |WHO|

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