Tuberculosis (TB) is caused by bacteria (Mycobacterium tuberculosis) and it mostly affects the lungs. It is spread through the air when people with lung TB cough, sneeze or spit. A person needs to inhale only a few germs to become infected.
About 85 percent of people who develop TB disease can be successfully treated with a 6-month drug regimen; treatment has the added benefit of curtailing onward transmission of infection.
Every year, 10 million people fall ill with tuberculosis (TB). Despite being a preventable and curable disease, 1.5 million people die from TB each year – making it the world’s top infectious killer. Globally, TB incidence is falling at about 2 percent per year and between 2015 and 2019 the cumulative reduction was 9 percent. This was less than halfway to the End TB Strategy milestone of a 20 percent reduction between 2015 and 2020.
The Government of India has set the target for achieving Sustainable Development Goals (SDGs) related to TB by 2025 as against the global target of 2030.
Accordingly, the Ministry of Health and Family Welfare prepared the National Strategic Plan (NSP) to achieve the SDG target of reduction in mortality due to TB by 90 percent; and reduction in the incidence of TB by 80 percent; by 2025, as compared to the 2015 baseline.
The NSP proposes bold strategies with commensurate resources to rapidly decline TB incidence and mortality in India by 2025, five years ahead of the global end TB targets and Sustainable Development Goals to attain the vision of a TB-free India. The main goal of the NSP is to achieve a rapid decline in the burden of TB, morbidity and mortality while working towards the elimination of TB in India by 2025.
India is now better prepared to address TB but complete elimination of the disease is mired with several challenges. A significant proportion of the population is undernourished, which leads to weakened immunity and TB reactivation. A considerable population also suffers from conditions that weaken the immunity, including diabetes, indoor air pollution from cooking stoves, or smoking, that increase the likelihood for progression to active TB. There are also several cases where inadequately treated TB may recur or relapse at any time.
Delay in diagnosis, inadequate treatment, high rates of recurrent TB, drug resistance, diabetes, HIV, undernutrition, urbanisation are important drivers for the persisting TB epidemic
The biggest challenge has been the scale of private sector engagement. Efforts need to be made to increase the participation of the private sector. There also has to be proper data on the long-term outcomes of treatments and the private sector can play a pivotal role in this. The high rate of recurrence is another cause of concern.
Although India has managed to scale up basic TB services in the public health system, the rate of TB decline is too slow to meet the 2030 Sustainable Development Goals (SDG) and 2035 End TB targets. While sufficient expertise exists, these resources have often been underutilised for quantitative analysis and improvements in TB control policy and implementation.
According to the 2019 Tuberculosis Profile of India collated by the WHO the total TB incidence in the country was 2640000. Total cases notified in India in 2019 was 24,04,815 of which the new and relapses figured at 2162323. For TB financing the 2020 National TB Budget was pegged at $497 million of which 85 percent was domestically funded.
Communication strategies should be revamped and designed with high visibility for demand generation and stigma reduction. India needs to spruce its research in TB with a focus on the development and validation of new tools and better diagnostics.
According to WHO, in 2019, the 30 high TB burden countries accounted for 87 percent of new TB cases. Eight countries account for two-thirds of the total, with India leading the count, followed by Indonesia, China, the Philippines, Pakistan, Nigeria, Bangladesh and South Africa.
About one-quarter of the world’s population is estimated to be infected by TB bacteria. Only 5-15 percent of these people will fall ill with active TB disease. The rest have TB infection but are not ill and cannot transmit the disease.
Ten countries accounted for 77 percent of the global gap between treatment enrolments and the estimated number of new cases in 2019 and thus will have a strong influence on progress in closing this gap. China and India accounted for 41 percent of the global gap.
The Global Tuberculosis Report 2020 maintains that worldwide, 7.1 million people with TB were reported to have been newly diagnosed and notified in 2019, up from 7.0 million in 2018 and a large increase from 6.4 million in 2017 and 5.7–5.8 million annually in the period 2009–2012.
The biggest contributors to the global increase were India and Indonesia, the two countries that rank first and second worldwide in terms of estimated incident cases per year. In India, notifications of people newly diagnosed with TB rose from 1.2 million to 2.2 million between 2013 and 2019 (+74 percent).
Global targets and milestones for reductions in TB incidence and TB deaths have been set as part of the Sustainable Development Goals (SDGs) and WHO’s End TB Strategy. SDG 3 includes a target to end the global TB epidemic by 2030. The End TB Strategy includes targets of a 90 percent reduction in TB deaths and an 80 percent reduction in the TB incidence rate.
TB and COVID
The COVID-19 pandemic is likely to have a medium-term impact on the number of people who develop TB each year. Although physical distancing policies may help to reduce TB transmission, this effect could be offset by longer durations of infectiousness, increased household exposure to TB infection, worsening treatment outcomes and higher levels of poverty.
In the absence of effective mitigation strategies, such as social protection and health insurance, severe economic contractions and loss of income (particularly among the most vulnerable populations) are likely to worsen some of the factors that determine TB epidemics, especially the prevalence of undernutrition, the GTR report mentions
The WHO also maintains that while the experience of COVID-19 infection in TB patients remains limited, it is anticipated that people with both TB and COVID-19 may have poorer treatment outcomes, especially if TB treatment is interrupted.
The BCG vaccine remains the only licensed vaccine against TB; it provides moderate protection against severe forms of TB (TB meningitis) in infants and young children. WHO recommends that, in countries with a high TB burden, a single dose of the BCG vaccine should be provided to all infants as soon as possible after birth. In countries with low TB incidence rates, provision of the BCG vaccine may be limited to neonates and infants in recognized high-risk groups, or to older children who are skin-test negative for TB infection.
Experts, however, feel the need to build research towards developing a new vaccine for TB that will address the challenges.
As in previous years, most available TB funding (85 percent ) in 2020 came from domestic sources, with Brazil, Russian Federation, India, China and South Africa providing 57 percent of the global total, according to WHO. International donor funding, as reported by national TB programmes (NTPs), increased from US$ 0.9 billion in 2019 to US$ 1.0 billion in 2020. The Global Fund to Fight AIDS, Tuberculosis and Malaria was the single largest source of international TB financing in 2020, while the United States remains the biggest bilateral funder of efforts to end TB.
The National Tuberculosis Programme of India (NTP) was initiated in 1962 and was originally designed for domiciliary treatment, using self-administered standard drug regimens. A revised strategy to control TB was pilot-tested in 1993. A full-fledged programme was started in 1997 and rapidly expanded with excellent results. This Revised National Tuberculosis Control Programme (RNTCP) that uses the DOTS (Directly Observed Treatment, Short-course chemotherapy) strategy achieved country coverage on World TB Day, March 24, 2006.
—Vanita Srivastava is an independent health and science journalist and is currently working as a Senior Project Scientist at IIT Delhi. The views expressed are personal.