Overview

• India has the highest estimated burden of tuberculosis infection (TBI) globally, with nearly 35-40 crores Indian population having TBI, of which 26 lakhs people (18-36 lakh) are estimated to develop tuberculosis (TB) disease annually.


• Several studies have shown that, on average, 5–10% of those infected will develop TB disease over the course of their lives, usually within the first 2 years after initial infection. The risk for TB disease after infection depends on several factors, the most important being immunological status. This risk is increased >25 times among contacts of bacteriologically confirmed TB patients compared to general populations, 16-21 times in case of HIV co-infection and 3-4 times in another immune-compromised status like diabetes, etc. Studies show 75% of people who develop TB disease after contact with a patient with active TB are estimated to do so within one year of TB diagnosis of the index patient and 97% within two years. Molecular fingerprinting studies further confirmed the probabilities of developing the disease within one, two, and five years as 45%, 62%, and 8,3%, respectively.


• Although early diagnosis and treatment of active TB remain a top priority in India, preventing TB by finding and treating TBI and active case finding (ACF) amongst high-risk groups (HRGs) are extremely important steps towards ending TB. The risk of developing TB disease after TB preventive treatment (TPT) decreases by approximately 60%, and the reduction can be up to 90% among people living with HIV (PLHIV).


• Prevention of TB disease by treatment of TBI is a critical component of the National Strategic Plan 2017-25 for Ending TB (NSP) in India by 2025. The NSP proposes a Detect-Treat- Prevent-Build approach and scaling up TPT would be key to hastening the rate of decline in TB incidence from 2.5% at present to 10% required annually. 


• It is crucial to adopt an integrated and comprehensive ‘cascade of care’ approach as a core strategy for delivering TPT services across India. This is so because, despite ambitious targets of ending TB by 2025 in India, there is a need to expand the scope and management options under PMTPT as a priority intervention to accelerate the decline in TB incidence. In the cascade of care approach, all target populations who are at risk of developing TB disease are systematically reached out, screened for TB disease and after ruling out TB disease, provided TPT as a part of continuum of care.