Alarm sounds about tuberculosis strains that are almost untreatable

More and more, startling epidemiological evidence signals that the number of tuberculosis strains resistant to most medications is increasing and that urgent efforts are needed to ensure that this problem does not become more widespread, according to an editorial in the Sept. 16 British Medical Journal.

The alarm was sounded in response to a study presented at the XVI International AIDS Conference in Toronto in August that documented a significant number of cases of extensive drug-resistant TB, or XDR-TB, as well as its deadly impact.

Researchers found that, out of 536 people in a South African town who had this infection from January 2005 to March 2006, 221 had a strain resistant to at least one medication. Of these people, 53 had a version resistant to all available antibiotics, and 52 of them died within a month of diagnosis.

"This is what we have uncovered in South Africa," said Gerald Friedland, MD, senior author and director of the AIDS program at Yale University in Connecticut. "It's probably the tip of the iceberg. It's going to be uncovered in other places as well."

In response to XDR-TB's emergence, the Centers for Disease Control and Prevention, in collaboration with the South African Medical Research Council and the World Health Organization, issued last month a seven-point emergency action plan. This document recommends taking a rapid survey to determine the full extent of the threat. It also urges increasing the capacity of public health officials to identify and combat outbreaks. A global task force is expected to be convened shortly.

Experts also warn that XDR-TB is not a problem exclusive to less-developed nations. According to a survey carried out by the CDC and published in the March 24 Morbidity and Mortality Weekly Report, 4% of U.S. tuberculosis cases occurring from 1993 to 2004 were resistant to all available drugs.

"Drug resistance has happened all over the world," said Dr. Friedland.