India’s efforts to eliminate tuberculosis could be undermined by persistent gaps in access to essential diagnostic services, particularly at the primary and secondary levels of the public health system, according to a new study published today in the peer-reviewed journal Microbiology Spectrum.
The study, “Evaluating the nationwide availability of essential diagnostics for tuberculosis toward achieving a TB-free India,” is one of the first multi-state assessments examining the implementation of India’s National Essential Diagnostics List (NEDL) for tuberculosis across different levels of public healthcare. The research analyzed national data on TB Treatment Units and Culture and Drug Susceptibility Testing (CDST) laboratories and assessed 327 public healthcare facilities across seven states and Delhi.
One of the most significant findings was a 61.56 per cent shortfall in CDST laboratory capacity nationally when compared with population-based requirements. The study found 97 CDST laboratories against 6,308 TB Treatment Units, substantially below the recommended ratio needed to support effective diagnosis and drug-resistance testing.
The researchers also found substantial gaps in access to essential TB diagnostics at the primary-care level. Only 4.94 per cent of surveyed Primary Health Centres (PHCs) had the complete set of essential TB diagnostics recommended for that level of care. Overall, complete essential diagnostic availability across the surveyed facilities ranged from 10.32 per cent to 66.67 per cent across the states, including Delhi.
The individual diagnostic figures were also concerning. Across the surveyed facilities, AFB smear microscopy was available in 78.46 per cent, while X-ray services were available in 51.28 per cent, cartridge-based nucleic acid amplification testing (CBNAAT) in 51.28 per cent, and fluorescence microscopy in only 30.95 per cent of the relevant facilities. At PHCs, X-ray availability was particularly limited, ranging from 0-10 per cent across the surveyed states.
“The central message of this study is that TB elimination is not simply a matter of finding and treating patients—it requires a diagnostic system capable of finding the right patients early and identifying drug resistance in time to guide appropriate treatment,” said Dr Mustafa Barbhuiya, corresponding author of the study.
India remains central to the global TB response. The World Health Organization's Global Tuberculosis Report 2025 estimates that 10.7 million people developed TB globally in 2024, with the South-East Asia Region accounting for the largest regional share. WHO has emphasized that continued progress toward ending TB will require intensified action, including stronger diagnosis and equitable access to care.
The study highlights a particular concern with the continued reliance on conventional diagnostic approaches at peripheral health facilities. AFB smear microscopy and chest radiography remain important components of TB screening and diagnosis, but their availability and limited sensitivity mean they cannot constitute the sole diagnostic strategy. These tests are not diagnostic for active tuberculosis.
The authors argue that rapid molecular diagnostics need to be expanded closer to the point of first contact, particularly through Community Health Centres and, where feasible, Primary Health Centres. At the same time, molecular testing needs to be complemented by a strong culture and drug-susceptibility-testing network capable of detecting and monitoring drug-resistant TB.
The study also draws attention to an often-overlooked component of TB care: laboratory tests required to monitor patients during treatment. Although availability of complete blood count (CBC) and comprehensive metabolic panel (CMP) testing was generally better than TB-specific diagnostic testing, important gaps remained, particularly at PHCs and CHCs. Such tests are important for monitoring treatment response and detecting adverse effects of anti-TB medicines.
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