WHO: Not sure if drug-resistant TB is worsening

Some health experts wondered why WHO's report failed to mention in detail one of the main drivers of drug resistance: bad medicines.

"Many substandard drugs are fakes, but we are also concerned about legitimately manufactured copies — mainly from India and China — which are not made to exacting high standards," said Philip Stevens, a health policy expert at the London think-tank International Policy Network.

Stevens said the lack of global TB data was troubling. "WHO doesn't really have a clue as to the true extent of the problem," he said. "It's difficult then, to start promoting targets and goals when you don't know what baseline you are starting from."