New Delhi [India], August 14: India’s fight against tuberculosis needs to go beyond treatment and case notification and urgently focus on strengthening diagnostic infrastructure at the point of care, according to a new peer-reviewed study published in Microbiology Spectrum, a journal of the American Society for Microbiology. The study, titled “Evaluating the nationwide availability of essential diagnostics for tuberculosis towards achieving a TB-free India,” provides a multi-state assessment of essential tuberculosis diagnostic services across public-sector healthcare facilities and a nationwide analysis of TB Treatment Units and Culture and Drug Susceptibility Testing (CDST) laboratories. The research team assessed 327 healthcare facilities across seven states and Delhi, while also analysing national-level data on TB Treatment Units and CDST laboratories.
The findings reveal a critical mismatch between the ambition of TB elimination and the diagnostic capacity available across India’s health system. A particularly important finding is the 61.56% gap in CDST laboratory capacity identified through the national analysis. The study found only 97 CDST laboratories against the number of TB Treatment Units required to provide adequate population coverage. The researchers say this has direct implications for India’s ability to identify drug-resistant tuberculosis and provide timely, appropriate treatment.
Diagnostic access remains uneven at the primary-care level
The study found that essential TB diagnostic services are particularly limited at the peripheral levels of the healthcare system.
Only 4.94% of surveyed Primary Health Centres (PHCs) had the complete set of essential TB diagnostics recommended for that level of care.
The assessment also found substantial variation in the availability of individual diagnostic modalities, including acid-fast bacilli microscopy, chest X-ray, cartridge-based nucleic acid amplification testing (CBNAAT), and fluorescence microscopy.
For a disease such as tuberculosis, where delayed diagnosis can prolong infectiousness and contribute to transmission, the researchers argue that access to appropriate diagnostics cannot remain concentrated in higher-level facilities.
“The question is not simply whether India has advanced TB diagnostic technologies. The more important question is whether a patient presenting at the first point of care can actually access the appropriate diagnostic test and, when necessary, testing for drug resistance.”
A study that underwent rigorous peer review
The study underwent multiple rounds of peer review in Microbiology Spectrum. Reviewers specifically examined the study’s sampling strategy, geographic representation, definition of diagnostic availability, private-sector coverage, human resources, utilization of diagnostic services, statistical methodology and relevance to laboratory equity.
The authors revised the manuscript substantially in response.
Importantly, the researchers clarified that “availability” in the study refers to the actual provision of diagnostic services at the facility at the time of assessment, verified through direct observation and structured questionnaires, including the presence of functional instruments and necessary reagents.
The authors also acknowledge that availability should not automatically be equated with utilization or full diagnostic capacity. The survey did not measure test volumes, patient footfall, referral delays or other barriers to access. The findings therefore primarily describe infrastructural readiness rather than actual utilization of diagnostic services.
The study does not claim that 327 facilities represent all of India
Responding to reviewer concerns, the authors deliberately revised the terminology from “nationwide assessment” to “multi-state assessment” for the facility-level survey.
At the same time, the national mapping of TB Treatment Units and CDST laboratories provides a broader picture of India’s TB diagnostic infrastructure.
The authors also acknowledge that the facility survey had operational and logistical constraints, with greater representation from Assam because of the research team’s established presence and collaborations in the region. The selected locations nevertheless included remote northeastern settings, high-population northern states and the metropolitan setting of Delhi, providing insight into different healthcare contexts.
Why this matters for India’s TB elimination strategy
The researchers emphasize that diagnostic infrastructure is more than the physical presence of a machine. A functioning TB diagnostic system requires equipment, reagents, trained personnel, maintenance, quality assurance, referral mechanisms, and access to drug-susceptibility testing.
The peer-review process prompted the authors to explicitly distinguish diagnostic service availability from fully functional diagnostic capacity. They note that facilities reporting diagnostic services may still experience operational constraints, including limitations related to personnel and maintenance.
The study also highlights the importance of strengthening laboratory networks rather than relying exclusively on individual technologies.
Rapid molecular tests have transformed TB diagnosis, but they need to be supported by a broader laboratory infrastructure capable of detecting and monitoring drug resistance. Culture and drug-susceptibility testing therefore remain an important component of a resilient national TB laboratory network.
Lessons beyond tuberculosis
According to the authors, the implications extend beyond TB.
“Tuberculosis provides a powerful example of why laboratory equity is a health-system issue. A diagnostic technology has limited public-health value if the populations most affected by disease cannot access it when and where they need it.”
The authors argue that India’s experience could inform the broader implementation of the National Essential Diagnostics List (NEDL) and efforts to strengthen diagnostic access for other major infectious and chronic diseases.
The study therefore calls for greater attention to equitable distribution of essential diagnostics, strengthening of peripheral laboratories, expansion of molecular testing, maintenance of culture and drug-susceptibility-testing capacity, and investment in the human resources required to operate these systems.
The research team is continuing its assessment of TB diagnostic infrastructure in other parts of India. The authors expect future analyses to provide more comprehensive state-level comparisons and examine diagnostic utilization and other dimensions of access that were beyond the scope of the present study.
The study was ultimately accepted for publication on June 27, 2026, following two rounds of revision and peer review. The authors describe the published work as an initial evidence base for understanding India’s TB diagnostic landscape and emphasize that the findings should be used to guide further systematic assessment rather than interpreted as a definitive census of every healthcare facility in the country.
Reference: Barbhuiya M, Chakraborty B, Laskar A, et al. Evaluating the nationwide availability of essential diagnostics for tuberculosis towards achieving a TB-free India. Microbiology Spectrum. 2026. DOI: 10.1128/spectrum.00703-26
About the study: The research was undertaken by investigators associated with the Foundation for Advancement of Essential Diagnostics (FAED) and collaborating institutions in India and the United States.
Full article: Microbiology Spectrum – published article
