WHO revises India's annual TB death estimates downward by 20-40% based on new data

New Delhi: The World Health Organization (WHO) has revised India's annual tuberculosis (TB) death estimates downward by approximately 20-40%, based on new cause-of-death reports provided by the Indian government to the UN health body.

The 2023 Global TB Report from the WHO presents new data indicating that since 2015, India's annual TB deaths have remained below 400,000, with figures ranging between 250,000 and 400,000 in 2020 and 2021. In contrast, the 2021 and 2022 editions of the report had estimated India's annual TB deaths at over 500,000.

Tereza Kasaeva, the Director of the Global Tuberculosis Programme at the WHO, told DH, "Previously published estimates for India used cause-of-death data from India's sample registration system. But the SRS data that were available for use were only for a period up to 2013. In the past year or so, official data for 2014-2019 have been published by the Office of the Registrar-General and Census Commissioner of India for the first time and these have now been used. These data show a lower percentage of total deaths caused by TB in India compared with what had been previously estimated based on data available for the period up to 2013."

The latest WHO report, released on Tuesday, estimated that TB caused 1.3 million deaths worldwide, with a significant drop in global TB death estimates since 2010. This decrease was mainly attributed to the revised estimates for India based on new SRS reports for 2014-2019, released by the Indian government earlier this year.

Another contributing factor to the changes in WHO estimates was the use of the Global Burden of Disease survey reports by the Institute of Health Metrics and Evaluation, Washington. The GBD estimates were consistently higher than those calculated using the SRS data.

An epidemiologist familiar with the new WHO TB death estimates and the GBD estimates noted that "GBD models make all sorts of assumptions about reclassifying some causes of death and other adjustments, so they may well have overestimated TB deaths in the past."

Studies conducted by Prabhat Jha at the University of Toronto, Canada, and collaborators had previously shown a steady decline in TB death rates in India between 2001 and 2020 in all age groups under 70. The overall number of TB deaths also decreased, from about 500,000 in 2001 to 293,000 in 2020, aligning with the new WHO estimate.

The Union Health Ministry in India announced that the WHO recognized India's efforts in reducing TB cases and deaths, resulting in a downward revision of TB mortality rates from 4.94 lakh (494,000) in 2021 to 3.31 lakh (331,000) in 2022, marking a reduction of over 34%. The ministry also noted that TB mortality in India had decreased by 18% between 2015 and 2022.

According to the WHO report, 33 high TB burden countries accounted for 87% of the world's TB cases in 2022, with two-thirds of the global total concentrated in eight countries. India led the list with 27% of the cases, followed by Indonesia (10%) and China (7.1%). Other countries in the top eight included the Philippines (7.0%), Pakistan (5.7%), Nigeria (4.5%), Bangladesh (3.6%), and the Democratic Republic of the Congo (3%).