India Moves To Scale Up Stool-Based TB Test For Children

India may soon add a stool-based diagnostic tool to its tuberculosis (TB) control strategy, particularly for children, with the Indian Council of Medical Research inviting expressions of interest (EoI) for the transfer and commercialisation of a novel paediatric TB detection technology.

The innovation, developed by the ICMR-National Institute for Research in Tuberculosis, enables the detection of Mycobacterium tuberculosis (MTB) and associated drug-resistance markers using stool samples. It is expected to address long-standing gaps in diagnosing TB in children, where conventional sputum-based methods often prove inadequate.

A senior scientist from the ICMR said that the Council plans to enter into licensing pacts with eligible companies to facilitate wider access and faster deployment. The selected firms will be allowed to undertake further development, manufacturing, and commercialisation of the technology in line with the Council’s intellectual property policy.

Tuberculosis in children continues to be underdiagnosed, largely due to the limitations of existing testing methods. Children are often unable to produce sputum samples required for standard diagnostic tests. Moreover, paediatric TB is typically paucibacillary, meaning it carries a lower bacterial load, making detection more difficult.

In many cases, diagnosis involves invasive procedures or is delayed due to limited access to appropriate testing facilities, particularly in resource-constrained settings. These challenges contribute to delayed treatment, increased complications, and continued transmission.

In this context, a stool-based nucleic acid amplification test (NAAT) offers a non-invasive and potentially scalable solution, said the scientist.

The new method uses a standardised protocol to concentrate stool samples, allowing detection of TB bacteria through molecular diagnostic techniques. It is compatible with platforms such as Line Probe Assay (LPA) and Xpert Ultra, and can also support conventional methods including smear microscopy and culture.

One of its key advantages lies in its expanded ability to detect drug resistance. While commonly used tools primarily identify resistance to rifampicin, the new protocol extends detection to both first-line and second-line anti-TB drugs. This could help clinicians make more informed treatment decisions, particularly in cases of drug-resistant TB, added the scientist.

The technology has reached Technology Readiness Level 5 (TRL-5), indicating that it has been validated in relevant settings and is ready for further scaling.

The scientist said that the importance of industry collaboration in translating this laboratory innovation into a widely accessible diagnostic tool is critical. Companies with established manufacturing facilities in India and a credible track record have been invited to participate, he added.

India continues to bear a significant share of the global TB burden, with children forming a vulnerable and often overlooked segment. Experts have long emphasised the need for child-friendly, non-invasive diagnostic methods to improve detection rates.

A stool-based test could enhance early diagnosis, particularly at the primary healthcare level, where access to advanced diagnostic tools remains limited. It may also reduce reliance on invasive sampling procedures, making testing more acceptable and accessible.

Improved detection of drug resistance is another critical benefit, as multidrug-resistant TB remains a growing concern in the country.

“If successfully commercialised, the stool-based NAAT could become an important addition to India’s TB diagnostic toolkit, particularly for children. It aligns with national efforts to strengthen early detection and treatment, and to move closer towards the goal of TB elimination,” said the scientist.

Diagnosing TB, especially in children under five, is crucial as, by the year 2030, the WHO End TB Strategy aims to decrease TB deaths by 90% and the incidence rate by 80%. “Hence, more advanced diagnostic techniques, including non-sputum-based specimens like oral swabs, stool, and urine, are paramount to achieving the End TB goal,” said Silla Varghese Thomas, Priya Rajendran, and Sivakumar Shanmugam from the Department of Bacteriology, National Institute for Research in Tuberculosis-ICMR, Chennai, in their review article in Frontiers in Pediatrics.