Epidemiological Profile and rpoB Gene Mutations in Pulmonary Tuberculosis Patients From Sulaymaniyah, Iraq: Evidence of Novel Genetic Variations and Beijing Lineage Emergence.

Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains a significant global public health concern, including in Iraq. This study investigated the epidemiology, molecular characteristics, and rifampicin resistance-associated mutations of pulmonary TB in Sulaymaniyah, Iraq, from May 2024 to May 2025. A total of 77 confirmed pulmonary TB cases were identified, yielding an incidence rate of 9.09 per 100,000 inhabitants. This rate is notably lower than those reported in other Iraqi cities and may reflect a regional, and possibly national, decline in TB burden. Contrary to global trends, females comprised the majority of cases (n = 47, 61%). The highest prevalence of TB was observed among individuals aged ≥ 60 years, which may be attributed to immunosenescence and waning protection from the BCG vaccine. Monthly case distribution indicated seasonal variation, peaking between October and March. Molecular genotyping of 50 clinical samples revealed predominantly non-Beijing strains (98%), with the first molecular evidence of Beijing lineage in Iraq, indicating potential cross-border transmission. Analysis of the rifampicin resistance-determining region (RRDR) of the rpoB gene in 22 samples revealed no resistance-associated mutations, but detected several synonymous and novel nonsynonymous mutations outside the canonical RRDR. These genetic variations may represent early evolutionary adaptations without current resistance implications. Limitations in surveillance and diagnostic capacity may contribute to underreporting and obscure the true TB burden. This study highlights the evolving molecular epidemiology of TB in Sulaymaniyah, emphasizing the importance of ongoing molecular surveillance to inform public health strategies and control efforts.