Laboratory Diagnosis of Tuberculosis: Comparative Evaluation of Traditional and Molecular Methods

Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains a major global health concern, particularly in low- and middle-income countries. Early and accurate diagnosis is essential for effective treatment, prevention of transmission, and control of drug-resistant strains. This review critically evaluates laboratory diagnostic approaches for TB, focusing on traditional methods such as sputum smear microscopy, culture techniques, and histopathology, alongside advanced molecular methods including cartridge-based nucleic acid amplification tests (CBNAAT), Truenat, line probe assays (LPA), and whole genome sequencing (WGS). Traditional methods, though cost-effective and widely accessible, are limited by low sensitivity and prolonged turnaround times. In contrast, molecular techniques provide rapid, sensitive, and specific detection, including early identification of drug resistance, which is crucial for managing multidrug-resistant TB. The review also explores the pathophysiology and morphology of TB, highlighting their relevance in diagnostic interpretation. Clinical features, complications, and laboratory monitoring strategies are discussed to emphasize the importance of integrated diagnostic approaches. The role of laboratory systems in treatment monitoring, public health surveillance, and prevention strategies is critically analyzed. Despite significant advancements, challenges such as cost, infrastructure requirements, and accessibility limit the widespread implementation of molecular diagnostics. Therefore, a combined approach integrating both traditional and molecular methods is essential to optimize diagnostic accuracy and patient outcomes. Future research should focus on point-of-care technologies, biomarker discovery, and cost-effective diagnostic solutions to strengthen TB control programs globally.