Observational study assesses MiniDock MTB diagnostic accuracy against Xpert in Indonesian TB patients

Background: Access to tuberculosis (TB) diagnostics remains limited in high-burden countries, partly due to centralised and complex testing. We evaluated MiniDock MTB, a low-complexity near point-of-care (nPOC) assay, in sputum for diagnostic accuracy and agreement with Xpert MTB/RIF Ultra (Xpert). Methods: From September 2024 to April 2025, presumptive pulmonary TB cases aged >28 days were consecutively enrolled at 15 community health centres, a lung clinic, and a lung hospital in Bandung, Indonesia. Sputum was tested with MiniDock MTB on sputum swab, Xpert, and liquid culture. We assessed diagnostic accuracy against microbiological and composite reference standards (CRS) and agreement with Xpert. Results: From 3051 individuals screened, 671 were eligible and included; 533 were adults (aged[≥]15 years), 138 were children. Overall, 126 were Xpert-positive and 132 culture-positive. In adults, MiniDock MTB sensitivity was 86.2% (110/116; 95% CI 78.8 - 91.3) and 55.8% (110/197; 95% CI 48.9 - 62.6) against liquid culture and CRS, respectively; small numbers of positive results precluded estimation in children. Specificity ranged from 96.8% to 98.8%. Overall agreement between MiniDock MTB and Xpert (excluding trace positive) was 94.8% (95% CI 92.6 - 96.3; K = 0.84). Positive percent agreement was 82.8% (95% CI 75.1 - 88.4) and 25% (95% CI 4.6 - 69.9) in adults and children, respectively, and reduced with lower bacillary burden (p = 0.004). Conclusions: Sensitivity of MiniDock MTB in sputum against liquid culture exceeded the WHO threshold for a sputum-based nPOC TB test in adults. There was high agreement with Xpert but reduced sensitivity in low-bacillary burden TB disease. Keywords: tuberculosis; diagnostic; MiniDock; sputum swab Funding: Gates Foundation INV-059052.