WHO: Drug-Resistant TB Spreading Faster Than Experts Feared

LONDON – Drug-resistant tuberculosis is spreading even faster than medical experts had feared, the World Health Organization warned in a report issued Tuesday.

The rate of TB patients infected with the drug-resistant strain topped 20 percent in some countries, the highest ever recorded, the U.N. agency said.

"Ten years ago, it would have been unthinkable to see rates like this," said Dr. Mario Raviglione, director of WHO’s "Stop TB" department. "This demonstrates what happens when you keep making mistakes in TB treatment."

Though the report is the largest survey of drug-resistant TB, based on information collected between 2002 and 2006, there are still major gaps: Data were only available from about half of the world’s countries.

In Africa, where experts are particularly worried about a lethal collision between TB and AIDS, only six countries provided information.

Experts also worry about the spread of XDR-TB, or extensively drug-resistant TB, a strain virtually untreatable in poor countries. When an XDR-TB outbreak was identified in AIDS patients in South Africa in 2006, it killed nearly every patient within weeks. WHO’s report said XDR-TB has now been found in 45 countries.

Globally, there are about 500,000 new cases of drug- resistant TB every year, about

5 percent of the 9 million new TB cases. In the U.S., 1.2 percent of TB cases were multi-drug resistant. Of those, 1.9 percent were extensively drug-resistant.