Background India has the highest number of patients with tuberculosis and multidrug-resistant tuberculosis in the
world. We used a transmission model to project the emergence of drug resistance in India due to incorrect tuberculosis
management practices in multiple sectors, including public and private providers, chemists, and non-allopathic
practitioners.
Methods We constructed a dynamic Markov model to represent India’s tuberculosis epidemic, including a probabilistic
framework refl ecting complex treatment-seeking pathways. Underlying drug resistance and the acquisition of drug
resistance during treatment were included. India-specifi c epidemiological data, including tuberculosis management
practices, were obtained from published literature. Outcomes, which included annual risk of infection, incidence of
new disease, prevalence of untreated tuberculosis, and tuberculosis-related mortality, were stratifi ed by underlying drug
resistance, as well as by health sector to understand how each sector contributes to the emergence of drug resistance.
Findings If tuberculosis management practices across sectors in India remain unchanged over the next 20 years, we
estimated a 47% increase in the incidence of isoniazid resistance, a 152% increase in multidrug-resistant tuberculosis
incidence, a 242% increase in prevalent untreated multidrug-resistant tuberculosis, and a 275% increase in the risk of
multidrug-resistant tuberculosis infection. By 2032, an estimated 85% of multidrug-resistant tuberculosis will be
primary multidrug-resistant tuberculosis compared with only 15% in 2012. The public sector contributed 87% of
acquired multidrug-resistant tuberculosis, related to irregular adherence; the remainder came from the private sector,
related to treatment non-completion. Chemists and non-allopathic practitioners do not treat with rifampicin, but
because of the high rates of inappropriate isoniazid-containing regimens, and treatment non-adherence, this would
generate isoniazid resistance.
Interpretation We predict a gradual transformation from the current epidemic of drug-susceptible tuberculosis to a
drug-resistant epidemic. Evidence-based strategies to improve provider practices and patient adherence across health
sectors are urgently needed to prevent this.