Is India on track in reducing TB incidence and deaths?
Like the fight against poverty and hunger, the progress made by mankind against tuberculosis (TB) in the years up to 2019 has either slowed, stalled, or reversed, and global TB targets are off track due to the COVID-19 pandemic. Globally, although the reported number of people newly diagnosed with TB decreased from 7.1 million to 5.8 million between 2019 and 2020, the number went up to 6.4 million in 2021. But is that good news? Let us try to find this out below.
The Global Tuberculosis Report 2022 prepared by the World Health Organisation (WHO) shows that 90 percent of global reduction in the reported number of people newly diagnosed with TB between 2019 and 2020 was observed in 10 countries, including India. The other nine countries were Indonesia, Philippines, China, Bangladesh, Pakistan, Myanmar, South Africa, Russia Federation and Kenya. Within that 90 percent, around 41 percent decrease in the reported number of people newly diagnosed with TB between 2019 and 2020 was contributed by India.
In comparison to 2019, almost 90 percent of the global reduction in reported number of people newly diagnosed with TB globally in 2021 was noticed in just 5 countries i.e., India, China, Indonesia, Philippines and Myanmar.
It should be noted that the reduction in the reported number of people newly diagnosed with TB is not at all good news. It is because such reductions suggest that the number of people with undiagnosed and untreated TB has grown, resulting first in an increased number of TB deaths and more transmission of infection and then, with some time lag, increased numbers of people developing TB.
That is why one can see a rise in the global number of TB deaths in 2020 as well as in 2021 vis-à-vis TB deaths in 2019. The global number of TB deaths was 1.4 million in 2019, 1.5 million in 2020, and 1.6 million in 2021. The global number of TB deaths among HIV-negative people was 1.2 million in 2019, 1.3 million in 2020, and 1.4 million in 2021.
In India too, a similar trend was observed. The estimated absolute number of TB deaths (both HIV-positive and HIV-negative TB) for the country was 4,50,000 in 2019, 4,80,000 in 2020 and 5,10,000 in 2021. In 2021, the WHO African and South-East Asia regions accounted for 82 percent of the combined total of TB deaths in HIV-negative and HIV-positive people; India alone accounted for 32 percent of such deaths.
Estimating TB deaths during the COVID-19 years
It was difficult for the WHO to produce estimates of TB disease burden during the pandemic years. So, in the absence of reliable direct measurements of the national number of TB cases and deaths from national disease surveillance systems, vital registration (VR) systems and population-based surveys in the period 2020–2021 in most low- and middle-income countries (LMICs), new methods for estimating TB mortality and incidence in these years were developed by WHO along with Imperial College, United Kingdom of Great Britain, and Northern Ireland (United Kingdom). These methods rely heavily on country-specific and region-specific dynamic models and have been extensively reviewed. Key assumptions are that reductions in the reported number of people newly diagnosed with TB reflect real reductions in TB case detection (rather than an increase in the underreporting of cases or a reduction in TB incidence) and a 50 percent reduction in TB transmission during periods of severe restrictions (lockdowns).
For 123 countries, estimates of the number of TB deaths among HIV-negative people for the period 2000–2019 are based on data on causes of death from national vital registration (VR) systems or mortality surveys, which collectively accounted for 60 percent of the estimated number of TB deaths (among HIV-negative people) globally in 2019. For 21 of these countries, including India, analyses of VR data and resulting estimates of TB deaths published by the Institute of Health Metrics and Evaluation (IHME) were used. For all other countries, TB mortality among HIV-negative people was estimated indirectly as the product of TB incidence and the case fatality rate (CFR) i.e., the percentage of people with TB who die from the disease. For all countries, TB mortality among HIV-positive people was estimated as the product of TB incidence and the CFR, with the latter accounting for the protective effect of antiretroviral treatment (ART). Estimates for 2020 and 2021 were based on country-specific dynamic models for 27 countries (including India) with the biggest absolute reductions in TB notifications during the COVID-19 pandemic (when these reductions departed from pre-2020 trends). The models were fitted to monthly or quarterly TB case notification data reported to WHO for the period from January 2020 and calibrated to pre-2020 estimates of TB incidence and mortality.
Global rise in TB incidence
Globally, an estimated 10.6 million people became TB victims in 2021, an increase of around 5 percent over 10.1 million in 2020, which reversed many years of slow decline. India, Indonesia, and the Philippines were found to be the major contributors to the global increase between 2020 and 2021. Collectively, TB incidence grew by nearly 0.4 million in these three countries. As per the Global TB Report 2022, this is consistent with their contributions to global reductions in the reported number of people newly diagnosed with TB in 2020 and 2021 vis-à-vis the pre-pandemic years.
The number of estimated TB incident cases for India was 29,60,000 in 2019, 28,50,000 in 2020, and 29,50,000 in 2021.
Importance of national TB prevalence surveys
Ideally, countries should rely on data routinely collected through national disease surveillance and vital registration (VR) systems in order to track the burden of TB disease in terms of TB incidence and TB mortality. Although national systems for notification (i.e., reporting) of TB cases exists in almost all countries, and most countries report national notification data to the WHO annually, in many countries (including most high TB burden countries) the number of notified cases each year is not a good proxy for the actual number of people who develop TB disease, for two reasons. The first is underreporting of people diagnosed with TB, especially in countries with large private sectors or in which people with TB seek care in public facilities that are not linked to the national TB programme and its associated reporting systems. The second is underdiagnosis, especially in countries with geographic or financial barriers to seeking health care. Many countries (including most high TB burden countries) do not have established national vital registration systems of high quality and coverage that can be used to reliably monitor the number of deaths and their cause. Thus, carrying out national TB prevalence surveys is the best way to directly measure the burden of TB disease in the population, states the Global TB Report 2022.
Results from national TB prevalence surveys can be used to inform national estimates of TB incidence in all age groups, and can thus help to track progress towards the milestones and targets for reductions in TB incidence set in the End TB Strategy.
According to the WHO's Global TB Report 2022, other benefits of national TB prevalence surveys include that they can be used to document health care seeking behaviour in the public and private sectors, assess variation in underreporting or underdiagnosis of TB by age and sex (using the ratio of prevalence to notifications), and quantify the extent of underreporting of people diagnosed with TB to national authorities. Findings from such surveys can help to inform the development or improvement of TB case finding, diagnosis and treatment interventions.
In 2019-2021, the first-ever national survey was completed in India; this was one of the largest surveys to date, with a sample size of about 3,20,000 people. Results from the national TB prevalence survey of India are not provided in the Global TB Report 2022. This is because these are currently under discussion between WHO and the National TB Elimination Programme of the Ministry of Health & Family Welfare.
How did India officially react to the findings of the Global TB Report 2022?
A press release by the Ministry of Health and Family Welfare (MoHFW) dated October 28, 2022, mentions that "[w]hile the COVID-19 pandemic impacted TB Programmes across the world, India was able to successfully offset the disruptions caused, through the introduction of critical interventions in 2020 and 2021 – this led to the National TB Elimination Programme notifying over 21.4 lakh TB cases – 18% higher than 2020." However, the press release by MoHFW does not make any effort to compare the case notifications of people newly diagnosed with TB in 2020 and 2021, vis-à-vis 2019.
The case notifications of people newly diagnosed with TB in India were 16,67,136 in 2015, 17,63,876 in 2016, 16,49,694 in 2017, 19,08,683 in 2018, 21,62,323 in 2019, 16,29,301 in 2020, and 19,65,444 in 2021. Between 2019 and 2020, India witnessed a reduction of 24.65 percent in case notifications of people newly diagnosed with TB. Between 2019 and 2021, our country faced a reduction of 9.1 percent in case notifications of people newly diagnosed with TB.
The press release by MoHFW adds that "India has, in fact, performed far better on major metrics as compared to other countries over time. India’s TB incidence for the year 2021 is 210 per 100,000 population – compared to the baseline year of 2015 (incidence was 256 per lakh of population in India); there has been an 18% decline which is 7 percentage points better than the global average of 11%. These figures also place India at the 36th position in terms of incidence rates (from largest to smallest incidence numbers)."
WHO's End TB Strategy requires that the TB incidence rate should be reduced by 20 percent between 2015 and 2020 (first milestone) and by 50 percent between 2015 and 2025 (second milestone). The target is to reduce the TB incidence rate by 80 percent between 2015 and 2030, and by 90 percent between 2015 and 2035. In the case of India, the TB incidence rate reduced by around 20.3 percent between 2015 and 2020. Hence, the first global milestone is met by India in terms of reduction in TB incidence rate. Please note that the TB incidence rates for India were 256 per lakh population in 2015, 249 per lakh population in 2016, 234 per lakh population in 2017, 224 per lakh population in 2018, 214 per lakh population in 2019, and 204 per lakh population in 2020.
The End TB Strategy of WHO also requires that the absolute number of TB deaths should be reduced by 35 percent between 2015 and 2020 (first milestone) and by 75 percent between 2015 and 2025 (second milestone). The target is to reduce the absolute number of TB deaths by 90 percent between 2015 and 2030, and by 95 percent between 2015 and 2035. For India, the absolute number of TB deaths grew by 2.12 percent between 2015 and 2020 as opposed to the first global milestone in terms of reducing absolute number of TB deaths. The estimated absolute number of TB deaths (HIV-positive and HIV-negative) in India was 4,70,000 in 2015, 4,60,000 in 2016, 4,60,000 in 2017, 4,60,000 in 2018, 4,50,000 in 2019, and 4,80,000 in 2020.
Tuberculosis profile: India, Global Tuberculosis Report 2022, World Health Organization, launched on 27 October 2022, please click here to access
Global Tuberculosis Report 2022, World Health Organization, launched on 27 October 2022, please click here, here, here, and here to access
Press release: WHO Global TB Report 2022, Ministry of Health and Family Welfare, Press Information Bureau, released on October, 2022, please click here to access
India TB Report 2022: Coming Together to End TB Altogether, produced by the Ministry of Health and Family Welfare, released in March 2022, please click here to access
End TB Strategy, World Health Organization, please click here to access
News alert: One in every four TB cases is from India, show a recent international report, Inclusive Media for Change, Published on Nov 7, 2019, please click here to access
Tuberculosis cases rise for the first time in years, says WHO, AP/ The Hindu, 28 October, 2022, please click here to access
Small Gains Made in Recovering COVID-Induced Losses in India's Fight Against TB: WHO Report -Banjot Kaur, TheWire.in, 28 October, 2022, please click here to access
TB nutrition aid falls short -Taran Deol, Down to Earth, 24 August, 2022, please click here to access
Centre to launch new anti-TB programme focused on nutrition, The New Indian Express, 4 August, 2022, please click here to access
The way to control tuberculosis -T Jacob John and Sushil Mathew John, The Hindu, 6 July, 2022, please click here to access
India reports sharp rise in tuberculosis last year as cases up 19% -Sumi Sukanya Dutta, please click here to access, Moneycontrol.com, 24 March, 2022, please click here to access
India's TB report must be seen in light of the country's slide in Hunger Index -Shah Alam Khan, The Indian Express, 26 October, 2019, please click here to access
Undernutrition, alcohol and smoking biggest TB risks in India: WHO -Sanchita Sharma, Hindustan Times, 20 October, 2019, please click here to access
Image Courtesy: Global Tuberculosis Report 2022
Tagged with: Diagnosis End TB Strategy Global TB Report National TB prevalence surveys national vital registration systems Notification Reporting TB TB deaths TB incidence rate TB Mortality Tuberculosis World Health Organisation