Relapse and Emergent Resistance With Novel Short-Course Regimens for Multidrug-Resistant Tuberculosis, United States, 2022-2024.

BACKGROUND: Bedaquiline, pretomanid, and linezolid with or without moxifloxacin (BPaL/M) are recommended oral 6-month treatment regimens for multidrug- or rifampin-resistant (MDR/RR) tuberculosis (TB). Since the US rollout of these regimens in 2019, the US Centers for Disease Control and Prevention (CDC) and partners have identified patients who failed or relapsed on these regimens.

METHODS: Here, we report a case series of US patients with TB treated with BPaL/M-containing regimens, who experienced adverse outcomes during the period 2022‒2024, including drug resistance, relapse, and treatment failure.

RESULTS: Clinical and public health outcomes were significant for US patients reported. There were 8 patients identified (n = 8). 5 (62.5%) were male, with a median age 57 years, 2 (25%) were previously treated for TB, and 8 (100%) presented with cavitary disease. This included a patient who died from infectious TB with acquired resistance after exposing over 100 healthcare workers, a waitress who was found to have highly infectious TB at the time of her relapse, and a son who contracted() with reduced activity to bedaquiline from his mother in a household transmission event.

CONCLUSIONS: These patients highlight consequences, both for the individual and public health, of relapse and treatment failure in real-life operational settings that may not be readily evident in well-controlled and well-resourced clinical trials. Despite the advent of shorter and better tolerated bedaquiline-based regimens, US clinicians continue to face challenges in managing drug-resistant TB. These data support the need for expert management of these patients beyond routine TB care, as well as the need for close monitoring and follow-up months after treatment completion.