Aggressive treatment regimens can successfully treat XDR-TB, MDR-TB

Aggressive treatment regimens successfully can treat nearly half of patients with extensively drug-resistant tuberculosis and can help prevent multi-drug resistant TB from developing into XDR-TB, according to a study conducted in prisons in Tomsk, Russia, and published Monday in the journal Lancet, Reuters reports. XDR-TB is resistant to the two most potent first-line treatments and at least two of the classes of second-line drugs.

For the study, Salmaan Keshavjee of Partners in Health, Brigham and Women's Hospital and Harvard Medical School and colleagues examined 608 patients with MDR-TB between September 2000 and November 2004. Four percent of the patients, or 29 people, had XDR-TB (Fox, Reuters, 8/24). None of the XDR-TB patients and 1% of the MDR-TB patients had HIV (Britt, Bloomberg, 8/25).

Patients received an individually tailored treatment program based on their particular TB strain, including at least five drugs to which their strain was susceptible (BBC News, 8/24). According to the study, the combination treatment of five effective TB drugs and two less effective TB drugs successfully treated 48.3% of the XDR-TB patients and 66.7% of the MDR-TB patients. A study published earlier this month in the New England Journal of Medicine reported similar results in HIV-negative XDR-TB and MDR-TB patients in Peru (Reuters, 8/24). The study was funded by the Bill and Melinda Gates Foundation and the Eli Lilly Foundation (Bloomberg, 8/25).

Keshavjee said the 48.3% treatment success rate among XDR-TB patients is "promising" because XDR-TB "has been touted as untreatable" (Reuters, 8/24). A 2006 study conducted in South Africa found that 52 of 53 XDR-TB patients died within a relatively short time of diagnosis. All of the people with XDR-TB in the South African study were HIV-positive (GlobalHealthReporting.org, 8/7). Keshavjee added that "it may be possible to slow the rise of XDR-TB deaths" and "reduce further transmission" of drug-resistant strains of TB through aggressive management "by ensuring that patients are correctly diagnosed as early as possible and put on appropriate treatment for the correct length of time" (Reuters, 8/24).

Reaction

John Moore-Gillon, spokesperson for the British Lung Foundation, said that the study is "very important" and demonstrates that it is "possible to deal with XDR-TB" but added that it is "very expensive" to implement aggressive drug treatment regimens. According to Moore-Gillon, treatment for XDR-TB is "extremely labor and resource intensive and has to be done within extremely well-structured TB programs." He added that treating XDR-TB costs "much more" than MDR-TB treatment. "The reason we have the problem is inadequate control of TB," Moore-Gillon said (BBC News, 8/24).

Helen Cox and Cheryl McDermid of Medecins Sans Frontieres in an accompanying commentary said that "aggressive treatment [of XDR-TB] is the logical strategy to provide the best chance of [treatment success] while avoiding the creation of additional drug resistance," but added that researchers "should be cautious in [their] hope to attain such success rates in settings with a high prevalence of HIV" (Bloomberg, 8/25).

An abstract of the study is available online.