ATLANTA, March 23 (UPI) -- Federal officials said Thursday tuberculosis strains resistant to drugs have increased over the past decade.
"It is critical to take steps now to prevent the further spread of highly-resistant TB," the Centers for Disease Control and Prevention said in a statement.
The findings, which appear in the CDC's journal Morbidity and Mortality Weekly Report, are the first global assessment of highly drug-resistant TB.
The survey, which included data from a global network of reference laboratories between 1993 and 2004, found extensively drug-resistant TB or multi-drug resistant TB (resistant to three of the six classes of second-line drugs) in 2 percent of isolates.
Extensively drug-resistant TB, or XDR TB, was detected in all regions of the world, including the United States, and now accounts for 15 percent or more of multi-drug-resistant TB cases in South Korea.
"Worsening drug resistance worldwide poses a serious threat to our ability to treat and control TB, as treating patients with drug-resistant TB is costly, drugs are toxic and expensive, and patients with XDR TB are virtually untreatable," the CDC said.
