Temporal trends and spatial variation in nontuberculous mycobacterial incidence among First Nations people in Queensland, Australia

Background: Nontuberculous mycobacteria (NTM) are environmental pathogens causing pulmonary and extrapulmonary infections. First Nations people in Australia experience higher burdens of communicable diseases, comorbidities, and systemic barriers to care, increasing NTM risk. This study examined the incidence and spatial distribution of NTM infections in First Nations people in Queensland. Methods: A retrospective longitudinal analysis was conducted using NTM notifications from the Queensland Health Notifiable Conditions Database, stratified by Indigenous status. Incidence was calculated using population denominators and Indigenous Region boundaries, with direct rate comparisons between 2011 and 2024. Results: Between 2001 and 2024, 717 NTM notifications were recorded from 606 First Nations people, with a significant male predominance among those aged 30-44 years ({chi}^2=21.63, P<0.0001). NTM incidence was higher in 2024 than in 2011, increasing from 4.6 to 26.3 per 100,000 (incidence rate ratio (IRR): 5.74, 95% confidence interval (CI): 2.97-11.08, P<0.0001). Although incidence in 2024 was lower than in the non-Indigenous population (35.81 per 100 000), the rate of increase was 4.4 times greater. Pulmonary infections predominated (569/717, 79.36%) and were more frequent in 2024 than in 2011 (IRR: 6.95, 95% CI: 3.00-19.75, P<0.0001). Extrapulmonary incidence increased by 140% from 2020 primarily due to an outbreak of Mycobacterium abscessus infections among incarcerated First Nations males. Marked geospatial heterogeneity was observed, with the greatest increases in incidence in the Brisbane, Rockhampton, Townsville-Mackay, and Cairns-Atherton Indigenous Regions (P<0.001). Conclusions: NTM incidence among First Nations people in Queensland has increased substantially, with a faster rate of rise than in the non-Indigenous population despite lower absolute incidence, consistent with under-ascertainment. These findings highlight gaps in detection and diagnostic access, alongside heterogeneous geographic and outbreak-associated transmission dynamics. Strengthening culturally appropriate surveillance and improving access to timely diagnosis are required to better define disease burden and inform targeted clinical and public health responses in First Nations and other underserved populations.