Field Validation of a Simplified DNA Extraction Protocol Suitable for qPCR Detection of <em>Mycobacterium tuberculosis</em> in Low-Resource Settings: A Prospective Cross-Sectional Feasibility Study

Tuberculosis remains a major global public health issue, particularly among vulnerable populations in resource-limited settings. This study evaluated a simplified DNA extraction protocol combined with a portable quantitative Polymerase Chain Reaction (qPCR) device for on-site detection of Mycobacterium tuberculosis DNA in low-resource environments. A total of 54 sputum samples were collected from a remote village and a penitentiary in southern Brazil. The simplified extraction method and qPCR were conducted directly in the field without sample transport. Among all samples, qPCR detected three positives (5.6%), while smear microscopy identified one case (1.9%), and culture yielded no positives. The approach demonstrated operational feasibility under field conditions, though the small number of positive samples precluded diagnostic accuracy analysis. These findings suggest that portable molecular diagnostics can support tuberculosis control in hard-to-reach populations by enabling rapid, on-site screening.