Tuberculosis

Tuberculosis (TB) is an airborne infectious disease caused by the bacterium Mycobacterium tuberculosis. India has made substantial progress in reducing the TB burden, with incidence declining by 21% and mortality reducing by 28% between 2015 and 2024.[1] Despite these gains, achieving the goal of TB elimination by 2030 will require a deeper understanding of transmission dynamics, epidemiology of TB in India, and the effectiveness of different control interventions.

How we address this challenge

By bringing programmatic data from the national TB programme together with dynamic transmission models, our work aims to describe the epidemic more accurately and to show where the programme's efforts are likely to benefit the most. We use mathematical modelling at the national and subnational levels to answer some of the relevant and specific questions co-created with the programmatic counterparts at the Central TB Division and states. We are addressing the following questions using modelling frameworks, customized for India.

• Develop transmission models for estimating the national and sub-national TB burden.
• Evaluate the effects of TB interventions.
• Build a ML model for prediction of poorer TB treatment outcomes.
• Evaluate the impact of nutrition supplementation on TB dynamics.
• Model the long-term epidemiological impact of Ni-kshay Poshan Yojana (NPY).

Ongoing work

We have developed a TB transmission model that incorporates disease specifications and patient care-seeking behaviour to better understand transmission dynamics. Using this framework, we have evaluated the impact of interventions on TB incidence and mortality. We are in the process of adapting this framework to the states and subsequently to the districts.

We have also investigated factors associated with treatment outcomes and conducted spatio-temporal analyses of TB comorbidities across states. We are also analyzing the impact of TB preventive therapy (TPT) by stratifying populations based on differential risk.

In addition, we have developed a mathematical model to provide recommendations to the NPY programme and support progress towards End TB targets by 2035.

Publications

• Raj YA, Parthasarathy R, Mitra M, Mehra S. Assessing the Impact of Interventions on Tuberculosis Control: India Based Modelling Framework. 2026. Preprint
• Parthasarathy R, Raj Y, Majumder N, Mitra M, Mehra S, Rao R, Rajan S. Predictors of treatment outcomes in adults with drug - sensitive Tuberculosis in Maharashtra, India: A retrospective study. 2026. Preprint

References

1. World Health Organization. (2025). Global tuberculosis report 2025.
   https://www.who.int/publications/i/item/9789240116924