Comprehensive analysis of tuberculosis burden trends and attributable risk factors in the BRICS countries from 1990 to 2021, with forecasts for the next 15 years

Abstract

Background:

The study was to elucidate a comprehensive view of the burden of tuberculosis (TB) from different dimensions.

Methods:

Data were sourced from the Global Burden of Disease 2021. We provided a comprehensive overview of all relevant measures and the associated age-standardized rates per 100 000 (ASR) across BRICS countries. And we analyzed risk factors contributed to TB-related deaths and disability-adjusted life years (DALYs). Additionally, temporal trends in the disease were delineated using a joinpoint regression model, while projections over the subsequent 15 years were generated using the Bayesian age-period-cohort model.

Results:

The global age-standardized incidence rate (ASIR) was 103 per 100 000 in 2021, which represented a 40.5% decrease since 1990. Notably, ASIR in China experienced a significant decline of 66.7%. Individuals aged 65 and above were high-risk group for TB. For the Russian Federation, the percentages of deaths and DALYs caused by multidrug-resistant tuberculosis and extensively drug-resistant tuberculosis were approximately 30% and 14% respectively in 2021. Although DS-TB still accounted for the highest proportion of about 55%, it was significantly lower in contrast to other countries, where the rate reached over 80%. And the gradual downward trends of ASIR and ASMR are expected to continue over the period from 2021 to 2036.

Conclusions:

The results indicated that the burden of TB in BRICS countries has decreased over the past 30 years. It highlights an urgent requirement to develop and implement relevant strategies in the prevention and control of TB based on country-specific development status.

Background

Tuberculosis (TB) represents a long-standing and persistent infectious disease which has afflicted humanity for millennia, posing a significant global threat to human health^[1]. The causative agent of this disease is the slow-growing bacterium M. tuberculosis^[2]. Due to the survival strategies of M. tuberculosis within host cells, coupled with its ability to evade the immune system, the control of TB prevalence is hindered, further aggravating the global TB burden^[1]. The rise of drug-resistant tuberculosis (DR-TB), notably including multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) increases the costs of diagnosing, treating and preventing TB, and imposes significant economic and social burdens on countries globally^[3]. In 2023, TB potentially regained its position as the leading cause of mortality attributed to a single infectious agent globally, after a three-year period during which it was surpassed by coronavirus disease (COVID-19)^[2]. With the implementation of the WHO’s End TB Strategy in 2014 and the UN Sustainable Development Goals established in 2015, both the UN and WHO have pledged to eliminate the TB epidemic by 2035^[4]. It is vital to comprehensively analyze TB burden trends and evaluate risk factors for tracking advancements toward the objectives of the End TB Strategy.

HIGHLIGHTS

• Tuberculosis burden stratified by BRICS-sex-age patterns and its associated risk factors were estimated.

• In BRICS countries, tuberculosis (TB) incidence rates rose with age, peaking in the 45–69 age group, highlighting the higher burden of the TB in the elderly.

• The proportion of drug-resistant TB in BRICS countries and different Socio-demographic Index (SDI) regions increased, especially in the Russian Federation.

• A downward trend in TB across BRICS was observed by our prediction through 2036, especially in the Russian Federation and China, but more efforts will be necessary to meet the objectives of the End TB Strategy.

BRICS countries, which include Brazil, the Russian Federation, India, China, and South Africa, are categorized together as they are all experiencing rapid economic growth. They account for almost half of the global population and are all high-burden countries for TB^[5]. Among BRICS countries, TB remains a major obstacle to public health. For instance, TB cases experienced a significant increase during the period from 2015 to 2019 in Brazil^[6]. In South Africa, it accounts for the deaths of 60 000 individuals each year^[7]. India accounted for 26% and China for 6.8% of all estimated incident cases of TB worldwide^[2]. Although each of them must cope with different challenges, BRICS countries are still recognized as leaders in TB control. They are the major financial source of TB management, providing much funding^[8]. The success of their TB control and treatment efforts is crucial for achieving the objectives of the global End TB Strategy (2016–2035).

While previous studies have examined historical TB mortality trends in BRICS using age-period-cohort analyses^[9] and infectious disease mortality patterns^[10], no comprehensive assessment has specifically addressed the TB burden and its attributable risk factors in BRICS. Adhering TITAN guidelines 2025 for transparent reporting^[11], our study filled this critical gap by presenting the first comprehensive analysis of TB burden trends and attributable risk factors from 1990 to 2021, with forecasts for the subsequent 15 years. This work not only advanced the understanding of evolving TB dynamics but also established an evidence base to monitor progress toward the WHO’s 2035 End TB Strategy targets. It further provided a framework for policy formulation and resource allocation strategies, ultimately contributing to public health TB prevention and control efforts.

Table 1.

All-age cases and age-standardized incidence, prevalence, mortality, and DALYs rate of tuberculosis in global and BRICS countries in 1990 and 2021

Location	Measure	1990		2021
		All-ages cases	Age-standardized rates per 100 000 people	All-ages cases	Age-standardized rates per 100 000 people
		n (95% UI)	n (95% UI)	n (95% UI)	n (95% UI)
Global	Incidence	8 598 520 (7 528 228, 9 854 794)	173.03 (152.88, 198.71)	8 407 133 (7 519 793, 9 393 767)	103 (92.21, 114.91)
	Prevalence	1 605 364 975 (1 440 332 859, 1 777 421 464)	30696.64 (27716.5, 33 776.96)	1 911 816 784 (1 733 433 144, 2 100 447 765)	23614.01 (21451.1, 26020.11)
	Deaths	1 778 869 (1 532 822, 1 980 801)	39.99 (34.16, 44.76)	1 162 796 (1 050 008, 1 313 985)	13.96 (12.61, 15.72)
	DALYs	82 679 773 (73 004 989, 91 407 746)	1650.59 (1457.64, 1824.72)	46 977 463 (42 482 994, 52 463 556)	580.26 (522.37, 649.82)
China	Incidence	1 167 808 (1 359 621, 1 001 441)	109.01 (124.61, 94.81)	617 726 (688 348, 549 548)	36.28 (40.47, 32.63)
	Prevalence	369 779 785 (420 948 319, 324 342 084)	31445.76 (35142.48, 27902.18)	491 548 380 (539 371 580, 445 855 387)	30557.45 (33531.31, 27692.69)
	Deaths	171 091 (204 908, 141 634)	20.09 (23.84, 16.68)	37 332 (49 368, 9309)	1.91 (2.51, 1.51)
	DALYs	7 325 730 (8 528 411, 6 221 452)	719.42 (837.38, 610.63)	1 375 510 (1 723 072, 120 820)	76.22 (94.45, 62.59)
Brazil	Incidence	71 346 (61 968, 82 486)	55.37 (48.68, 63.34)	70 946 (61 021, 82 901)	29.6 (25.57, 34.54)
	Prevalence	49 615 965 (44 325 062, 54 874 448)	35058.16 (31768.14, 38390.52)	53 710 150 (47 852 330, 60 341 104)	22668.45 (20338.3, 25346.57)
	Deaths	8526 (8276, 8783)	7.85 (7.58, 8.07)	5576 (5307, 5806)	2.24 (2.13, 2.33)
	DALYs	419 608 (402 648, 438 148)	328.64 (317.46, 341.19)	221 135 (209 212, 232 047)	90.42 (85.49, 95.28)
India	Incidence	2 656 904 (2 173 904, 3 262 442)	392.62 (323.9, 477.11)	2 955 264 (2 599 262, 3 383 727)	214.39 (188.98, 244.86)
	Prevalence	269 840 574 (227 071 987, 323 383 612)	31294.34 (26746.2, 36800.19)	379 022 522 (334 241 752, 424 826 762)	26792.21 (23701.88, 29963.6)
	Deaths	600 796 (533 098, 680 033)	110.29 (96.66, 125.54)	399 044 (344 242, 493 758)	32.94 (28.47, 40.79)
	DALYs	26 439 968 (23 781 895, 29 256 577)	3910.27 (3490.87, 4366.49)	15 057 801 (13 108 012, 18 233 001)	1119.71 (977.01, 1355.66)
South Africa	Incidence	201 340 (176 410, 225 850)	561.56 (500.16, 625.1)	271 242 (237 371, 310 915)	458.05 (403.15, 517.17)
	Prevalence	17 061 022 (15 315 928, 18 660 471)	46979.3 (42773.02, 50732.69)	25 212 356 (23 045 234, 27 640 333)	44165.9 (40517.48, 48272.8)
	Deaths	20 649 (17 508, 25 711)	73.33 (61.4, 91.83)	22 958 (20 546, 26 533)	45.88 (41.06, 52.78)
	DALYs	1 156 855 (998 525, 1 404 265)	3420.54 (2935.5, 4192.02)	1 029 770 (922 549, 1 174 218)	1855.04 (1661.27, 2115.3)
Russian Federation	Incidence	185 620 (160 109, 216 713)	114.86 (99.48, 134.33)	100 152 (83 637, 122 296)	61.11 (51.13, 74.89)
	Prevalence	50 734 045 (45 516 222, 56 439 587)	31996.48 (28795.64, 35616.45)	25 587 230 (22 340 839, 29 219 029)	15640.9 (13840.02, 17752.85)
	Deaths	10 603 (10 424, 10 773)	6.08 (5.98, 6.18)	5538 (5061, 5983)	2.81 (2.58, 3.03)
	DALYs	457 638 (439 376, 476 944)	274.1 (263, 286.14)	230 972 (212 476, 250 300)	128.7 (118.65, 138.75)

DALYs, disability-adjusted life years; UI, uncertainty interval.

Table 2.

The AAPC in ASIR of tuberculosis from 1990 to 2021

Location	AAPC	95% CI		t	P
		Lower	Upper
China	−3.491	−3.609	−3.372	−56.638	0.000
Brazil	−1.997	−2.022	−1.973	−157.427	0.000
India	−1.951	−2.040	−1.863	−42.816	0.000
South Africa	−0.639	−0.740	−0.538	−12.336	0.000
Russian Federation	−1.956	−2.436	−1.474	−7.895	0.000

ASIR, age-standardized incidence rate; AAPC, average annual percent change; CI, confidence interval.

Methods

GBD 2021 overview

Covering 204 countries, territories, and 811 subnational locations from 1990 to 2021, the GBD study is managed by the Institute for Health Metrics and Evaluation at the University of Washington, which regularly updates the results of the global burden of disease research since 1990 on its website^[12]. The GBD regularly updated the health metrics, particularly including the population forecasts up to the year 2100^[13].

And the GBD study employs the disability-adjusted life years (DALYs) as the primary health metric to assess both years of life lost (YLLs) due to premature mortality quantify and years lived with disability^[12]. DALYs represent health loss from fatal and nonfatal outcomes, encompassing the sum of YLLs and years lived with disability^[14]. Metrics were also analyzed in association with Socio-demographic Index (SDI), a composite indicator that typically includes factors such as per capita income, average educational attainment, and total fertility rate within a specific population.

Disease definition

TB remains a major contributor to morbidity and mortality globally, caused by M. tuberculosis as an infectious bacterial disease^[15]. In GBD, a hierarchical system is often employed to divide the causes into four levels, ranging from the most extensive (Level 1; e.g. communicable, maternal, neonatal, and nutritional diseases), to the most specific (Level 4; e.g. lower respiratory infections). TB, being a part of respiratory infections and TB, is classified as a Level 3 cause. The subtypes of TB are further broken down and are considered Level 4 causes.

In the present study, we report estimates for DS-TB, MDR-TB, and XDR-TB. DS-TB is characterized by susceptibility to the first-line drugs isoniazid and rifampicin. MDR-TB is characterized by resistance to rifampicin and isoniazid yet remains sensitive to any fluoroquinolone and second-line injectable drug. XDR-TB is characterized by resistance to rifampicin, isoniazid, any fluoroquinolone, and at least one second-line injectable drug^[16].

Data source

The latest data utilized in the research were sourced from GBD 2021, available via the Global Health Data Exchange online platform (https://vizhub.healthdata.org/gbd-results/). Employing the GBD 2021 dataset, we described and estimated the trends in TB burden in BRICS using four standard epidemiological measures: incidence, prevalence, death, and DALYs, along with their corresponding age-standardized rates (ASR) between 1990 and 2021. The crude and age-standardized estimates, as well as the corresponding 95% uncertainty intervals (UI) were gathered. All measures extracted from GBD were stratified by age, sex, and three subtypes of TB (MDR-TB, XDR-TB, DS-TB) over the period from 1990 to 2021.

Furthermore, based on five SDI quintiles, we collected data to investigate the disparities in disease burden across regions with high, high-middle, middle, low-middle, and low SDI levels. Our study also focused on risk factors contributing to TB mortality and DALYs including three key risk factors (smoking, high alcohol use, and high fasting plasma glucose [HFPG]) provided by the GBD study. Prior studies have elucidated the hierarchy of risk factors and provided detailed definitions of exposure^[17].

Statistical analysis

First, to elucidate the extent and directionality of temporal trends, the joinpoint regression analysis was used to determine the average annual percent change (AAPC) and 95% CI for four metrics: ASIR, ASPR, ASMR, and ASDR from 1990 to 2021. When AAPC >0 and the P-value <0.05, it indicates a statistically significant increasing trend in ASR over the study duration; when AAPC <0 and P-value <0.05, it shows a decreasing trend in the ASR; when P ≥ 0.05, it suggests no significant change in the rate. Finally, a Bayesian age-period-cohort (BAPC) analysis was executed using BAPC and INLA packages in R.

We utilized joinpoint software (v5.1.0, Statistical Research and Applications Branch, National Cancer Institute, USA) to carry out joinpoint regression analysis. And the statistical analysis and data visualization were performed with R software (version 4.4.1). A two-tailed P-value less than 0.05 was considered statistically significant.

Results

Description of the burden of TB globally and in BRICS countries

Incidence of TB

Globally, while the incident cases of TB showed a slight decrease from 8 598 520 (95% UI: 7 528 228–9 854 794) in 1990 to 8 407 133 (7 519 793–9 393 767) in 2021, the ASIR fell from 170.03 (152.88–198.71) to 103 (92.21–114.91) per 100 000 population. Conversely, despite an increase in the total number of TB incidence cases over the same period in India and South Africa, these countries experienced significant declines in ASIRs, highlighting progress in disease control despite the rise in overall cases.

Prevalence of TB

China had high prevalence of TB cases in both 1990 and 2021, respectively accounting for about 23.03% and 25.71% of the global total. Compared to 1990, the most significant reductions in ASPR of TB were observed in Brazil (35.34%) and the Russian Federation (51.12%) in 2021, resulting in a relatively reduced burden of TB.

Mortality of TB

On a global scale, significant reductions have been observed in both the total mortality number and the ASMR. Nations such as China, Brazil, India, and the Russian Federation have each noted considerable declines. Conversely, South Africa has witnessed an increase in overall mortality, whereas the ASMR has notably decreased.

DALYs of TB

From 1990 to 2021, the DALYs of global and the BRICS have all decreased, with China experiencing the steepest decline of 81.22% (from 7 325 730 to 1 375 510), while South Africa had the smallest reduction rate of only 10.99% (from 1 156 855 to 1 029 770). A consistent decline in ASDR was observed from 1990 to 2021.

Overall, the results of these measures showed that India ranks first among the BRICS, followed by China.

Trends of TB from 1990 to 2021

The joinpoint regression analysis indicated a generally significant downward trend in the ASRs of TB among BRICS countries from 1990 to 2021 (Fig. 1).

Figure 2.

Trends of the age-standardized rates (ASRs) for tuberculosis from 1990 to 2021. (A) Age-standardized incidence rate (ASIR). (B) Age-standardized prevalence rate (ASPR). (C) Age-standardized mortality rate (ASMR). (D) Age-standardized DALYs rate (ASDR).

ASRs, age-standardized rates; ASIR, age-standardized incidence rate; ASPR, age-standardized prevalence rate; ASMR, age-standardized mortality rate; ASDR, age-standardized DALYs rate.

Figure 1.

A comprehensive view depicting the structure of the literature.

SDI, Socio-demographic Index; DALYs, disability-adjusted life years; ASR, age-standardized rate; DS-TB, drug-susceptible tuberculosis; MDR-TB, multidrug-resistant without extensive drug resistance tuberculosis; XDR-TB, extensively drug resistance tuberculosis; APC, annual percentage change; AAPC, average annual percent change; ASPR, age-standardized prevalence rate; ASDR, age-standardized DALY rate.

A notable decline of ASIR was observed in India compared to the other BRICS countries (Fig. 1A). In the Russian Federation, the trend increased first from 1990 to 2003, and then decreased thereafter until 2021. Meanwhile, the analysis revealed a notable downward trajectory in the ASPR of TB, exhibiting a consistent pattern across both Brazil and the Russian Federation (Fig. 1B and Supplemental Digital Content Table 1, available at: http://links.lww.com/JS9/E446). The trend observed in the ASDR plots is similar to that observed in the ASMR data (Fig. 1D).

Age-specific burden of TB in 1990 and 2021

The incidence and mortality rates generally increased with advancing age groups up to the oldest age group (≥95 years) basically across the BRICS. Interestingly, patterns in burden by age were similar across years from 1990 to 2021 for India and the Russian Federation. Compared to other countries, South Africa and India exhibited higher incidence rates across all age groups in 1990 and 2021 (Fig. 3A and B). The rate of prevalence was highest in South Africa in both 1990 and 2021 across all age groups among the BRICS (Fig. 3C and D). Moreover, it’s remarkable that the peak prevalence rates in China, Brazil, India, and the Russian Federation were all observed at 45–69 years in 2021 generally. In contrast to Brazil and the Russian Federation, whose mortality rates exhibited minimal fluctuation, India demonstrated persistently elevated mortality rates among older age groups, peaking in the 80–84 and 90–94 age groups in both years (Fig. 4).

Figure 5.

Tuberculosis age distribution of ASR in BRICS countries in 1990 and 2021. (A) ASMR in 1990, (B) ASMR in 2021, (C) ASDR in 1990, (D) ASDR in 2021.

ASR, age-standardized rate; ASMR, age-standardized mortality rate; ASDR, age-standardized DALYs rate.

Figure 6.

All-age crude deaths and DALYs of tuberculosis by cause category in 1990 and 2021. (A) Crude deaths, (B) crude DALYs.

DALYs, disability-adjusted life years; DS-TB, drug-susceptible tuberculosis; MDR-TB, multidrug-resistant without extensive drug resistance tuberculosis; XDR-TB, extensively drug resistance tuberculosis.

Figure 3.

Average annual percentage change (AAPC) analysis of tuberculosis across BRICS countries from 1990 to 2021. (A) ASIR, (B) ASPR, (C) ASMR, (D) ASDR.

AAPC, average annual percentage change; ASIR, age-standardized incidence rate; ASPR, age-standardized prevalence rate; ASMR, age-standardized mortality rate; ASDR, age-standardized DALYs rate; CI, confidential interval.

Figure 4.

Tuberculosis age distribution of ASR in BRICS countries in 1990 and 2021. (A) ASIR in 1990, (B) ASIR in 2021, (C) ASPR in 1990, (D) ASPR in 2021.

ASR, age-standardized rate; ASIR, age-standardized incidence rate; ASPR, age-standardized prevalence rate.

Cause-specific burden of TB in 1990 and 2021

We found that DS-TB resulted in substantially more total deaths and DALYs than MDR-TB and XDR-TB in 1990 and 2021 across the BRICS and different SDI regions. The most striking increases were observed in the Russian Federation, where the XDR-TB mortality rate reached 14.5%, and in high SDI regions, where the rate was 4.5%. It’s worth noting that the MDR-TB mortality rate in the Russian Federation has reached 31.1% in 2021, an increase of 12 times from the 2.4% in 1990.

Risk factors

Ranking of the contribution of risk factors to the TB burden

Figure 7 reveals that the ranking of TB disease burden caused by various risk factors has remained basically unchanged except for HFPG in 2021 compared to 1990. The top five most significant risk factors at the most granular level globally were ranked as follows: smoking, high alcohol use, HFPG, high body mass index, and low physical activity.

Figure 7.

Risk factors ranked globally for deaths (A) and DALYs (B) for 1990 and 2021, with mean change of counts and age-standardized deaths and DALYs rate.

SDI, Socio-demographic Index; ASMR, age-standardized mortality rate; ASDR, age-standardized DALYs rate; DALYs, disability-adjusted life years.

TB mortality and DALYs attributable to individual risk factors

BRICS countries level

The contribution of smoking to the deaths in China and the Russian Federation indicated that the risk was significantly higher than in other BRICS countries in both 1990 and 2021. Strikingly, the percentage for TB mortality due to smoking, which ranked as the second risk factors in males, was over four times higher than females in 1990 and 2021. It is worth noting that compared to 1990, both men and women were more likely to have a greater burden of TB due to HFPG in 2021.

Compared to 1990, there was a general trend for males to have a higher proportion of the three risk factors than females, especially in China and the Russian Federation in 2021.

SDI regions level

The proportion of deaths for both sexes attributable to HFPG rose gradually with increasing SDI in 1990, slightly different from 2021. What deserves attention is that between 1990 and 2021, the percentage of smoking-attributable deaths and DALYs was higher for males compared to females in all SDI regions and BRICS countries. In conclusion, for these three risk factors, males bear a heavier burden of TB disease.

Future forecasts of the burden of disease in TB

Generally, there was an observed overall downward trend in both ASIR and ASMR across BRICS countries. The ASIR for both males and females was projected to decline gradually, with estimates indicating approximately 96 and 73 per 100 000 population in 2035 globally. Significant declines of ASIR and ASMR were observed by different sexes in the Russian Federation and China, a pattern expected to continue through 2036 (Figs. 8 and 9). According to the projection, the ASPR and ASDR were predicted to decrease in the coming years (Supplemental Digital Content Figures 1, 3, 6, 7, available at: http://links.lww.com/JS9/E446).

Figure 8.

Proportion of tuberculosis deaths and DALYs attributable to smoking and high alcohol use, high fasting plasma in 1990 and 2021. (A) Proportion of tuberculosis deaths in 1990. (B) Proportion of tuberculosis DALYs in 1990. (C) Proportion of tuberculosis deaths in 2021. (D) Proportion of tuberculosis DALYs in 2021.

SDI, Socio-demographic Index; DALYs, disability-adjusted life years.

Figure 9.

Trends in tuberculosis ASIR from 2021 to 2036 in female. (A) Brazil, (B) China, (C) India, (D) Russian Federation, (E) South Africa, (F) Global.

ASIR, age-standardized incidence rate; BAPC, Bayesian age-period-cohort.

Discussion

Over the last three decades, although the declines of incidence and death cases were all observed globally, it indicated that the first End TB Strategy was far from being realized until 2021^[18,19]. According to the report, BRICS are among the countries with the highest burden of TB. They account for 46% of all new TB cases and 40% of all TB-related mortality^[5]. Our findings revealed a general downward trend in ASR across these five countries from 1990 to 2021. This decline may be attributed to the significant increase in per capita health expenditure observed in Brazil, China, South Africa, and India following the establishment of BRICS countries in 2006. Between 1995 and 1997, the World Bank adopted Directly Observed Treatment Short-course (DOTS) as its primary strategy for TB control. Notably, World Bank funding and development assistance for TB control was primarily concentrated in South Asia and Africa, with India and China being the foremost recipients of such commitments from 1986 to 2017^[20]. Among them, India achieved 100% DOTS coverage in 2006 by revising its National Tuberculosis Control Program (RNTCP)^[21]. Undoubtedly, these are some of the contributing factors to the decline in TB incidence during this period. Research indicated that a direct correlation was observed between the economic downturn of the 1990s and the exacerbation of the TB epidemic in the Russian Federation^[22]. The economic crisis contributed to a surge in the TB incidence rate, reaching its peak during this period. Interestingly, our findings further revealed that the Russian Federation experienced even more substantial declines in TB cases after the BRICS founded. From 2000 to 2010, the government implemented stringent measures to curb the spread of TB, also resulting in a decline in cases.

Based on their political commitment, resource allocation, and multifaceted collaboration, BRICS countries have achieved remarkable progress in the prevention, control, and treatment of TB. They have deepened their cooperation and made significant contributions in multiple related fields, such as diagnostic tests, vaccines, and novel drug therapies, demonstrating their commitment to advancing the fight against TB and embodying the rationality of policymaking and research input^[23–25]. Specifically, BRICS countries have allocated substantial domestic funding to TB care, which has had a marked effect on improving access to high-quality services for vulnerable populations^[26]. For instance, the Russian Federation invested over a billion United States dollars annually in TB care^[5].

Furthermore, we conducted a group-based investigation in BRICS countries. Our findings revealed that the incidence rates generally rise with advancing age groups in the BRICS. Similarly, a study also ascertained an augmented incidence of TB in individuals aged over 65 years^[27]. Although the relative contribution of aging varied across BRICS countries, it is an important risk factor for developing TB, with inflammation being recognized as a key contributing element^[28,29]. Moreover, elderly individuals face other numerous challenges, including diminished lung function, immune-senescence, adverse drug effects, poor tolerance to anti-TB medications, as well as the presence of age-related comorbidities^[30]. Individuals over 60 years old in India and South Africa continue to exhibit higher mortality rates relative to other nations. As previously mentioned, some individuals are infected with M. tuberculosis without showing clinical symptoms. With the decline in immune function that comes with aging, dormant lesions are more likely to reactivate, contributing to a higher mortality rate from pulmonary TB in elderly patients^[31]. To tackle the increasingly heavy TB burden in the elderly population, it is critical to strengthen the screening of high-risk groups and optimize treatment regimens for elderly patients. For instance, early detection can be achieved through tuberculin skin test and interferon-gamma release assays^[32]. Dosing of anti-TB drugs should be individualized based on liver and kidney function to mitigate the incidence of adverse drug reactions, while strengthening comprehensive chronic disease management for TB remains imperative.

The Russian Federation experienced a notably high burden of drug-resistant TB, with approximately 30% of deaths and 14% of DALYs attributed to MDR-TB and XDR-TB, respectively in 2021. Drug-resistant TB is not merely a regional concern but has escalated into a global challenge, significantly impacting public health. In contrast to DS-TB, patients with MDR-TB or XDR-TB must require a treatment regimen consisting of more than seven drugs over a longer duration^[33]. This treatment regimen is associated with a high failure rate and significant drug toxicity. Moreover, approximately 50% of MDR and XDR pulmonary TB patients remain uncured. These individuals continue to spread the disease. The financial burden is substantial: although cases of MDR-TB represent less than 5%–10% of the total TB burden, they often consume over 50% of the national TB budget^[34]. Based on DOTS, DOTS-Plus incorporates second-line anti-TB drugs, extends treatment duration, and emphasizes personalized treatment tailored to patients, aiming to boost treatment success rates, particularly in high-drug-resistance regions. This strategy is particularly applicable to low-and middle-income countries and regions with limited resources^[35]. Even though the WHO proposed the DOTS-Plus strategy in 1998, our results show that, compared with 1990, the proportion of MDR-TB in BRICS countries was still increasing in 2021. Therefore, in response to the continuously rising proportion of MDR-TB, it is imperative to popularize the GeneXpert rapid molecular diagnostic technology in primary healthcare facilities. Meanwhile, BRICS countries should strengthen their drug-resistance detection networks, promote international collaboration, and advance the development of vaccines and new drugs.

Globally, TB is concentrated in low- to middle-income countries. Indeed, studies have suggested that the prevalence of TB depends on the socioeconomic development status and social protection measures^[36]. It’s worth noting that the COVID-19 pandemic has a catastrophic influence in society and economy, leading to the rising of poverty, which is a crucial driving factor to TB pandemic^[37]. Factors contributing to the transmission of TB include limited access to healthcare, poor nutrition, and substandard living conditions, etc^[38]. Consequently, implementation targeting socioeconomic interventions that fight poverty is pivotal in tackling the high burden of TB.

Our study confirmed previous findings^[39–41], indicating that high alcohol use, HFPG and smoking behavior may elevate the risk of TB in BRICS. The estimates revealed the evident sex differences in the deaths and DALYs due to smoking. In fact, data suggested that males exhibit a higher susceptibility to active pulmonary diseases compared to females^[42]. The elevated TB burden in males is significantly impacted by non-biological factors, notably smoking. Increased attention is also being devoted to the impacts of biological factors on TB. The BRICS countries are experiencing rapid economic expansion and exhibit marked trends toward urbanization and globalization. This is accompanied by a progressively increasing risk of disease burden attributed to chronic diseases, such as diabetes^[43]. As showed in other research, HFPG, one of the diagnostic criteria for diabetes, impacts the disease burden of other diseases, including TB^[44]. In a comparison between 1990 and 2021, we found that high fasting plasma glucose (HFPR) accounted for larger proportion of deaths and DALYs in BRICS countries. A cohort study indicates that TB patients with HFPG exhibit intensified clinical symptoms, lung involvement and higher bacterial burden^[45]. Impaired blood glucose management not only compromises treatment outcomes for TB but also correlates with increased mortality rates^[46]. Focusing on carrying out innovative strategies to address the heavy burden of HFPR might be beneficial to TB control programs. In conclusion, regarding the higher TB burden due to smoking and alcohol consumption, BRICS countries should enforce stricter policies on tobacco and alcohol control, conduct community-based monitoring of smoking and alcohol use, and intensify health education initiatives. Metabolic diseases such as diabetes should be integrated into the TB prevention and control system. For example, blood glucose levels should be simultaneously tested during TB screenings.

Based on the WHO’s End TB Strategy 2035 milestones, we predicted the ASIR and ASMR by 2035. There has been a decline across BRICS countries, particularly with notable reductions in the Russian Federation and China. From 2015 to 2035, the global reduction in ASIR among females was 27%, and the ASMR was 51%. Despite these encouraging decreases, it is imperative that BRICS countries intensify their efforts to achieve the 2035 goal of reducing mortality by 95% and incidence rates by 90%, to less than 10 cases per 100 000 population, ultimately aiming to end the TB epidemic. The predicted rates in South Africa and India were significantly higher than their counterparts. South Africa faces barriers such as the frequent occurrence of medicine stockouts, HIV infection, drug-resistant TB, etc^[47,48]. The severe TB burden in India may be attributed to a series of barriers, including inadequate funding, poor diagnostic facilities, under-reporting, and low treatment success rates. To address these issues, measures such as strengthening the health system, upgrading diagnostic capabilities, incorporating the latest diagnostic technologies, and advocating for increased budgetary support are essential for leading India closer to a TB-free future^[49].

The GBD results may contain inaccuracies owing to the lack of actual observational data. Furthermore, the failure to collect data from certain low-income countries or remote regions poses a risk of underestimating the actual burden of TB. Lastly, the inability to obtain precise exposure information in epidemiological studies prevents the quantification of associated risks.

Conclusions

Over the past three decades, the descending trend of TB burden has been observed, which is expected to keep on in the future. Nowadays, setting policies and tailoring educational interventions are very crucial to reduce the impact of risk factors on the burden of TB. Ultimately, this research could provide valuable insights for TB prevention and control, guiding the allocation of healthcare resources in response to the varying conditions across BRICS countries.

Ethical approval

Not applicable.

Consent

Not applicable.

Sources of funding

This study was supported by Inner Mongolia Academy of Medical Sciences public hospital research joint fund project (No. 2024GLLH0255).

Author contributions

Investigation, visualization, and writing – original draft: X.M.Z.; methodology, formal analysis, and writing – original draft: M.R.G.; funding acquisition and conceptualization: X.F.S.; writing – review & editing: A.E.A.; project administration, supervision, and validation: G.R.W. and L.X.X. All authors have read and agreed to the published version of the manuscript

Conflicts of interest disclosure

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Research registration unique identifying number (UIN)

Not applicable.

Guarantor

Xiaomeng Zhang and Abualgasim Elgaili Abdalla.

Provenance and peer review

Not commissioned, externally peer reviewed.

Data availability statement

The data utilized in this study could be accessed openly through GBD 2021 online database (http://ghdx.healthdata.org/gbd-results-tool), as described in the Methods section.