Helen Cox, from the Wellcome Centre for Infectious Diseases Research in Africa (Cape Town, South Africa) write an editorial that a diagnostic test that can accurately determine the complete drug-susceptibility profile of the infecting strain or strains of Mycobacterium tuberculosis would make it possible to give patients the correct treatment and thereby decrease the amplification and onward transmission of drug resistance.
Allix-Béguec and colleagues bring us a step closer to this goal. On the basis of their result, public health authorities in England, the Netherlands, and New York have already decided to discontinue phenotypic drug-susceptibility testing of isolates that are predicted by sequencing to be pansusceptible to these first-line drugs — a policy change with substantial cost- and time-saving benefits. So what comes next? To advance this approach, all mutations associated with resistance to all existing, repurposed, and new antituberculosis drugs must be discovered.
However, bringing individualized therapy based on whole-genome predictions of susceptibility to patients in high-burden, resource-limited settings will be challenging, to say the least. Globally, only 22% of the 6.3 million people with newly diagnosed tuberculosis in 2016 had access to rifampin drug-susceptibility testing. However, previous programmatic failures, while underscoring the challenges, should not preclude us from aiming to provide the same standard of care for all patients with tuberculosis regardless of where they reside.