Global burden of MDR-TB and XDR-TB: trends, inequities, and future implications for public health planning.

Background: Drug-resistant tuberculosis (TB) remains a major global health threat, reflecting disparities in healthcare capacity, access, and socioeconomic development. Previous research often lacks geographic breadth. This study provides a comprehensive assessment of the global, regional, and national burden of Multidrug-resistant TB without extensive drug resistance (MDR-TB) and extensively drug-resistant TB(XDR-TB) from in Global Burden of Disease Study (GBD) 2021 Study 1990 to 2021, with a focus on distributional inequities. The findings aim to guide resource prioritization, inform targeted interventions, and reduce the burden in high-risk populations.

Methods: We systematically assessed the global, regional, and national burden of MDR-TB and XDR-TB, along with their change trends from 1990 to 2021, using data from the GBD 2021 database. The indicators included age-standardized incidence rate (ASIR), prevalence rate (ASPR), mortality rate (ASMR), and disability-adjusted life-years rate (ASDR). ASDR was analyzed in conjunction with the sociodemographic index (SDI) for a comprehensive assessment. Health inequalities were quantified using the slope index of inequality (SII) and concentration index (CCI). Frontier analysis estimated the achievable outcomes across different development levels, while decomposition analysis identified the key factors driving changes in disease burden.

Results: In 2021, the global ASIR of MDR-TB was 5.42 per 100,000 population [95% uncertainty interval(UI): 3.17, 9.34]), and the ASIR of XDR-TB was 0.29 per 100,000 population (95% UI: 0.21, 0.42). From 1990 to 2021, the ASIR of MDR-TB [AAPC = 0.14%, 95% confidence interval (CI): 0.13, 0.14] and XDR-TB (AAPC = 0.01%, 95% CI: 0.01, 0.02) both showed an increasing trend. The ASIR and ASMR of MDR-TB increased in low and low-middle SDI regions. Similarly, the ASIR and ASMR of XDR-TB increased in all five SDI regions. The ASIR of MDR-TB increased in 155 countries, with the largest increase observed in Somalia (AAPC = 1.79%, 95% CI: 1.67, 1.92). The ASIR of XDR-TB increased in all countries. From 1990 to 2021, both absolute and relative health inequalities in the ASDR of MDR-TB and XDR-TB have grown. In addition, the ASIR and incidence of MDR-TB and XDR-TB are negatively correlated with SDI.

Conclusion: The burden of MDR-TB/XIDR-TB is projected to increase, with persistent disparities concentrated in low-SDI settings. Targeted public health strategies-including improved resource allocation, infrastructure development, and community health education-are essential to reduce inequities. Strengthening these efforts may enhance global TB control and advance progress toward health equity.