antitubercular agents

Ethambutol (EMB) resistance can evolve through a multistep process, and mutations in the ubiA (Rv3806c) gene appear to be responsible for high-level EMB resistance in Mycobacterium tuberculosis. We evaluated the prevalence of ubiA and embB (Rv3795) mutations in EMB-resistant strains originating from Africa and South Korea. No differences in embB mutation frequencies were observed between strains from both origins. However, ubiA mutations were present in 45.5% 6.5% of the African EMB-resistant isolates but in only 9.5% 1.5% of the South Korean EMB-resistant isolates. The ubiA mutations associated with EMB resistance were localized to regions encoding the transmembrane domains of the protein, whereas the embB mutations were localized to regions encoding the extramembrane domains. Larger studies are needed to investigate the causes of increased ubiA mutations as a pathway to high-level EMB resistance in African countries, such as extended EMB usage during tuberculosis treatment.

Assessing the state of country readiness for the introduction of new, child-friendly anti-tuberculosis formulations can highlight potential bottlenecks, facilitate early planning, and accelerate access to appropriate treatment for children with tuberculosis (TB). To understand pathways and potential obstacles to the introduction of new pediatric formulations, we performed a desk review of key policy documents and conducted 146 stakeholder interviews in 19 high-burden countries. Issuance of World Health Organization (WHO) guidance serves as the trigger for considering adoption in most countries; however, the degree of alignment with WHO recommendations and duration ofintroduction processes vary. Endorsement by experts and availability of local evidence are leading criteria for adoption in upper-middle- and high-income countries. Ease of administration, decreased pill burden, and reduced treatment costs are prioritized in low- and lower-middle-income settings. Countries report an average of 10 steps on the path to new treatment introduction, with core steps taking between 18 and 71 months. The process of new treatment introduction is complicated by diverse country processes, adoption criteria, and evidence requirements. Challenges differ between low- and middle-to-high-income countries. Responsiveness to the unique hurdles faced across settings is important in ensuring a sustainable market for improved pediatric anti-tuberculosis treatment.

Background: The current tuberculosis (TB) treatment landscape has been studied extensively, but researchers rarely consider how it creates challenges or opportunities for future regimen change.

To explore the process, major players and procedural success factors for recent public sector TB regimen changes, we conducted 166 interviews of country stakeholders in 21 of the 22 TB high-burden countries (HBCs).Stakeholders described 40 distinct regimen changes for drug-susceptible TB. Once countries committed to considering a change, the average timing was ∼1 year for decision-making and ∼2 years for roll-out. Stakeholders more often cited concerns that were program-based (e.g., logistics and cost) rather than patient-focused (e.g., side effects), and patient representatives were seldom part of decision making. Decision-making bodies in higher-income HBCs had more formalized procedures and fewer international participants. Pilot studies focused on logistics were more common than effectiveness studies, and the evidence base was often felt to be insufficient. Once implementation started, weaknesses in drug management were often exposed, with additional complications if local manufacturing was required. Best practices for regimen change included early engagement of budgeting staff, procurement staff, regulators and manufacturers. Future decision makers will benefit from strengthened decision-making bodies, patient input, early and comprehensive planning, and regimens and evidence that address local, practical implementation issues.

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