Risk of rifampicin resistance emergence after incomplete first-line tuberculosis treatment

Tuberculosis (TB) treatment is lengthy and causes side-effects, making treatment completion challenging. Some patients are “lost to follow-up” (LTFU) before completing treatment. Patients sometimes subsequently return to care if symptoms motivate them, or if health systems and/or personal issues that caused LTFU are resolved. Case–control studies have established that drug-susceptible TB treatment and incomplete adherence were risk factors for relapse with drug-resistant TB, but its frequency and the lengths of incomplete treatment that pose the greatest risk are unknown [1, 2]. We aimed to estimate the risk of recurrent TB, and specifically rifampicin-resistant TB (RIF-R), after rifampicin-susceptible TB (RS-TB) treatment and how these risks vary depending on previous RS-TB treatment length.