How can we overcome the barriers to treating drug-resistant TB?

Almost 1 in 20 cases of tuberculosis worldwide is resistant to multiple drugs (known as multidrug-resistant TB or MDR-TB) and the World Health Organization has called for a massive scale up in public health efforts to tackle these cases. In this week's PLoS Medicine, a group of MDR-TB experts outlines its recommendations on conducting research that would help in the scale up. MDR-TB can be effectively treated using second-line TB drugs, though these drugs are more expensive, less potent, and less well tolerated than first-line drugs. Fewer than 2% of all patients with MDR-TB are receiving appropriate second-line treatment. The WHO has therefore called for a dramatic scale up of MDR-TB treatment as a routine component of TB control, setting a target of treating 1.6 million patients with MDR-TB by 2015. Pilot projects of MDR-TB management (known as "programmatic management of drug-resistant TB" or PMDT) in five low income settings showed treatment success rates of 59%-83%.

Frank Cobelens (KNVC Tuberculosis Foundation) and colleagues, writing on behalf of the Working Group on MDR-TB of the Stop TB Partnership, lay out their "prioritized research agenda." The agenda identifies the most important barriers to scaling up the treatment of MDR-TB and prioritizes the research questions to be addressed to overcome these barriers.

Their research priorities include:

• new and improved tools for testing patients to see if they have drug-resistant TB
• clinical trials of simplified and shorter second-line treatments for MDR-TB
• new and improved strategies for diagnosis of drug-resistant TB, for helping patients complete the whole course of drug treatment, and for controlling the spread of the infection
• understanding geographic variations in the occurrence of drug resistance
• clinical trials to test whether giving TB drugs to people who came into contact with patients with drug-resistant TB prevents them from developing resistant TB.

With increasing recognition of drug-resistant TB worldwide, say Cobelens and colleagues, "the time has come to move PMDT in resource-limited settings beyond the limited, pilot project phase."

Source: Public Library of Science