LONDON — Drug-resistant tuberculosis is spreading even faster than medical experts had feared, the World Health Organization warned in a report 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 the 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.
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 United States, 1.2 percent of TB cases were multidrug resistant. Of those, 1.9 percent were extensively drug resistant.
Last year, an Atlanta lawyer who was believed to have XDR-TB caused great concern among international air passengers after he flew to Europe and back after being told not to travel. Andrew Speaker, 31, was detained upon his return to the U.S. and underwent treatment at National Jewish Medical and Research Center in Denver. Doctors later determined he had a less severe case of drug-resistant TB than XDR-TB.
The highest rates of drug-resistant TB were in Eastern Europe. High rates of drug-resistant TB were also found in China and India, the world’s two most populous nations that together are home to half the world’s cases.
Drug-resistant TB arises when primary TB treatment is poor. Countries with strong treatment programs, like the U.S. and other Western nations, should theoretically have very little drug-resistant TB.
With growing numbers of drug-resistant TB patients, there is concern some national health systems will soon be overwhelmed.
Experts said new drugs are needed if the outbreak is to be curbed, along with new diagnostic tests to identify drug-resistant TB strains faster — current tests take about a month.
WHO said a new diagnostic test able to provide results within a day is being tried in South Africa and Lesotho.
