About one in 10 new cases of tuberculosis worldwide is resistant to at least one of the common drugs used to treat the disease, according to a new survey.
Resistance to multiple drugs - a problem that renders the disease untreatable in most parts of the world - is seen in about 1.4 percent of new cases. The problem is especially prevalent in Southeast Asia and parts of the former Soviet Union, the survey found.
“We are here today to issue an urgent warning to all countries that TB may soon become difficult or impossible to treat,” said Sally A. Shelton-Colby, an official of the U.S. Agency for International Development, at a news conference where the survey results were released Wednesday.
“If tuberculosis were a new disease, the world would spare no expense to fight it,” said Arata Kochi, director of TB programs for the World Health Organization, which helped organize the study. “Now, while we have been looking the other way … the germ has mutated into drug-resistant strains, making itself a more difficult and deadly enemy to combat.”
The study was conducted by four public health agencies from 1994 to 1997. Tuberculosis bacteria were sampled in 35 countries and regions of countries that together contain about 20 percent of the world’s population.
In some places, laboratories capable of testing for drug resistance also had to be built. The project is the first organized attempt to gauge the magnitude of the problem drug-resistant TB.
Tuberculosis is the most common serious infectious disease in the world. About 7 million new cases, and slightly more than 2 million deaths, occur each year.
The bacterium usually infects the lungs, which allows the disease to be transmitted through the air, especially in crowded, closed environments.
Normal, non-drug resistant cases of the disease are curable 98 percent of the time, but treatment requires use of four drugs and takes at least six months. When those two conditions are not met, drug-resistant strains of the TB bacterium can emerge.