Hope for multidrug-resistant TB patients

Rapid diagnostic test and shorter, cheaper treatment signal new hope for multidrug-resistant tuberculosis (MDR-TB) patients, according to a new recommendation of World Health Organisation (WHO).

At less than US$ 1000 per patient, the new treatment regimen can be completed in 9–12 months. Not only is it less expensive than current regimens, but it is also expected to improve outcomes and potentially decrease deaths due to better adherence to treatment and reduced loss to follow-up.

The conventional treatment regimens, which take 18–24 months to complete, yield low cure rates: just 50% on average globally. This is largely because patients find it very hard to keep taking second-line drugs, which can be quite toxic, for prolonged periods of time. They therefore often interrupt treatment or are lost to follow-up in health services.

The shorter regimen is recommended for patients diagnosed with uncomplicated MDR-TB, for example those individuals whose MDR-TB is not resistant to the most important drugs used to treat MDR-TB, known as second-line drugs. It is also recommended for individuals who have not yet been treated with second line drugs.

The most reliable way to rule out resistance to second-line drugs is a newly recommended diagnostic test for use in national TB reference laboratories. The novel diagnostic test – called MTBDRsl – is a DNA-based test that identifies genetic mutations in MDR-TB strains, making them resistant to fluoro-quinolones and injectable second-line TB drugs.

This test yields results in just 24-48 hours, down from the 3 months or longer currently required. The much faster turnaround time means that MDR-TB patients with additional resistance are not only diagnosed more quickly, but can quickly be placed on appropriate second-line regimens.