Resistant tuberculosis: Factors associated with unsuccessful treatment outcomes in Loreto, Peru, 2015-2023

Abstract Background Drug-resistant tuberculosis (DR-TB) remains a major challenge for TB control, with treatment success rates in Loreto, Peru, consistently below national averages. Nearly half of DR-TB patients in this Amazonian region experience loss to follow-up, treatment failure, or death, underscoring the need to identify region-specific factors associated with unsuccessful outcomes. Methods Retrospective cohort study including 417 MDR-TB cases registered in the national TB system in Loreto between 2015 and 2023. The unsuccessful treatment outcomes analyzed included loss to follow-up, mortality and therapeutic failure. Binary and multivariate logistic regression analyses were performed to identify risk factors associated with unsuccessful outcomes. Results Of the total number of cases, 49.5% had unsuccessful outcomes: 34.1% due to treatment dropout, 3.6% treatment failure, and 11.8% mortality. In the multivariate analysis, the factors significantly associated with unsuccessful outcomes were age between 18 and 30 years (OR: 2.8; CI: 1.1-7.1), alcoholism (OR: 3.76; CI: 1.1-12.7), drug addiction (OR: 4.48; CI: 1.2-17.2) and MDR-TB (OR: 2.2; CI: 1.2-3.8). Conclusions The identified risk factors should be the focus of priority programmatic interventions and future research aimed at optimizing regional strategies for TB control in Loreto.