PARIS, Feb 5: Africa, India and other developing countries are awash in fake or sub-standard drugs for tuberculosis, fuelling the rise of treatment-resistant strains of TB, according to a survey published on Tuesday.

Investigators in the United States asked local people in 19 cities in 17 countries to purchase isoniazid and rifampicin, the frontline antibiotics for TB, from a private-sector pharmacy.

The samples were then examined by chromatography, a technique that detects chemical signature, for their active ingredient.

They were also tested for disintegration, to see if they properly broke up in water at body temperature within 30 minutes.

Out of 713 samples, 9.1 per cent failed these basic quality control tests, according to the probe, published in the International Journal of Tuberculosis and Lung Disease.

Around half of the failed samples had zero active ingredients, “making them likely to contribute to drug resistance,” it said.

Resistance to TB drugs develops when treatment fails to kill the bacteria that causes it—either because the patient fails to follow their prescribed dosages or, as in this case, the drug doesn't work.—AFP