Epidemiological mapping of drug-susceptible and resistant tuberculosis in 30 WHO high-burden countries: <i>Three decades of GBD 2023 trends, projections to 2043 and concordance with WHO estimates</i>

Objectives: Tuberculosis (TB) continues to drive infectious mortality worldwide. The study characterized the evolution of drug-susceptible TB (DS-TB), multidrug-resistant TB (MDR-TB), and extensively drug-resistant TB (XDR-TB) in 30 WHO high-burden countries, linking current patterns to long-term trends, age structure, and forward-looking scenarios to 2043. Methods: Using GBD 2023 estimates for 1990–2023, we extracted incidence, mortality, and DALYs as age-standardized rates (ASR) per 100,000 with 95% uncertainty intervals. Temporal dynamics were summarized with Estimated Annual Percent Change (EAPC) and extended linearly to 2043. GBD incidence and mortality were compared against WHO national TB series for 2010–2023. Results: Overall TB incidence ASR declined in 28/30 countries between 1990 and 2023, ranging from a 79.2% reduction in Bangladesh to a 24.9% increase in the Philippines. Mortality and DALY ASR decreased in 29/30 countries. DS-TB incidence dropped in 28/30 settings, while MDR-TB incidence rose in 28/30, from -62.5% in China to +23,603% in Kyrgyzstan. The MDR/RR-TB burden shifted toward older adults (≥ 55 years) in countries such as China (+22 percentage points), whereas youth contributions remained high in Nigeria (∼40%). Projections assuming constant EAPC suggest continued DS-TB declines but sustained MDR-TB in Eastern Europe and Central Asia. Conclusion: The MDR-TB remains concentrated and often increasing with limited detectable XDR-TB. Age-tailored interventions, universal drug-susceptibility testing, scale-up of all-oral second-line regimens, and adherence support are critical to reverse resistant-TB trajectories while preserving gains against DS-TB.