Difficulties obtaining the drugs could be attributed to nationwide shortages, shipping delays and a complicated process for procuring new drugs that are still being tested, according to a National Tuberculosis Controllers Association survey of health departments.
The final results of the 2010 survey were released on Thursday and cited by the Centers For Disease Control and Prevention (CDC), which said possible solutions could include obtaining drugs from foreign manufacturers, stockpiling them, and creating an expedited approval process for new drugs.
"These shortages interfere with our ability to successfully treat TB," Kenneth Castro, director of the CDC's division of Tuberculosis Elimination, said in an interview on Thursday.
Multidrug-resistant tuberculosis accounts for about 1.5 percent of all cases in the United States, Castro said.
The survey found that the shortages and other problems that hindered access to the second-line drugs could promote development of drug resistance, the CDC said.
In the survey of 26 health departments that treated tuberculosis patients who were resistant to conventional drugs, 81 percent reported having trouble during the previous five years finding or paying for medicine that would be effective.
Tuberculosis is caused by airborne bacteria. Most cases can be cured with a six-month combination of four drugs, but patients resistant to the standard drugs face up to 24 months of taking five to six drugs that are "less effective, more toxic, and more costly than first-line drugs," the CDC said.
The United States had about 10,528 cases of tuberculosis in 2011 and there were 529 deaths from tuberculosis in 2009, according to the latest full year CDC statistics available.
More than half of the health departments surveyed said difficulty finding adequate drugs for the multidrug-resistant tuberculosis, delayed treatment of their patients, the CDC said.
However, the CDC cautioned that because only 54 percent of the 61 health jurisdictions asked responded to the survey, the results might not accurately represent the national tuberculosis drug-shortage problem in general.
Of the 33 health departments that responded, 26 had multidrug-resistant cases of tuberculosis in the five years covered and 21 of those had difficulty obtaining the second-line drugs needed to treat the cases.
(Reporting by David Beasley; Editing by David Bailey)