Time trends in tuberculosis mortality across the BRICS: an age-period-cohort analysis for the GBD 2019

Abstract

Background: Tuberculosis is the leading cause of death from a single infectious agent among the HIV-negative population and ranks first among the HIV-positive population. However, few studies have assessed tuberculosis trends in Brazil, Russia, India, China and South Africa (BRICS) or with an emphasis on HIV status. This study assesses the time trends of tuberculosis mortality across the BRICS with an emphasis on HIV status from 1990 to 2019.

Methods: We obtained tuberculosis data from the Global Burden of Disease 2019 study (GBD 2019). We calculated the relative proportion of tuberculosis to all communicable, maternal, neonatal, and nutritional diseases by HIV status across the BRICS. We used age-period-cohort modelling to estimate cohort and period effects in tuberculosis from 1990 to 2019, and calculated net drift (overall annual percentage change), local drift (annual percentage change in each age group), longitudinal age curves (expected longitudinal age-specific rate), and period (cohort) relative risks.

Findings: There were 549,522 tuberculosis deaths across the BRICS in 2019, accounting for 39.3% of global deaths. Among HIV-negative populations, the age-standardised mortality rate (ASMR) of tuberculosis in BRICS remained far higher than that of high-income Asia Pacific countries, especially in India (36.1 per 100 000 in 2019, 95% UI [30.7, 42.6]) and South Africa (40.1 per 100 000 in 2019, 95% UI [36.8, 43.7]). China had the fastest ASMR reduction across the BRICS, while India maintained the largest tuberculosis death numbers with an annual decrease much slower than China's (-4.1 vs -8.0%). Among HIV-positive populations, the ASMR in BRICS surged from 0.24 per 100 000 in 1990 to 5.63 per 100 000 in 2005, and then dropped quickly to 1.70 per 100 000 in 2019. Brazil was the first country to reverse the upward trend of HIV/AIDS-tuberculosis (HIV-TB) mortality in 1995, and achieved the most significant reduction (-3.32% per year). The HIV-TB mortality in South Africa has realised much progress since 2006, but still has the heaviest HIV-TB burden across the BRICS (ASMR: 70.0 per 100 000 in 2019). We also found unfavourable trends among HIV-negative middle-aged (35-55) adults of India, men over 50 in the HIV-negative population and whole HIV-positive population of South Africa, and women aged 45-55 years of Russia. China had little progress in its HIV-positive population with worsening period risks from 2010 to 2019, and higher risks in the younger cohorts born after 1980.

Interpretation: BRICS' actions on controlling tuberculosis achieved positive results, but the overall improvements were less than those in high-income Asia Pacific countries. BRICS and other high-burden countries should strengthen specified public health approaches and policies targeted at different priority groups in each country.

Funding: National Natural Science Foundation of China (82073573; 72074009), Peking University Global Health and Infectious Diseases Group.

Keywords: BRICS; HIV-negative; HIV-positive; Mortality; Tuberculosis.

Figure 1

Age-standardised mortality rates, total number of deaths resulting from tuberculosis, and relative proportion of tuberculosis to all death causes across Brazil, Russia, India, China, and South Africa between 1990 and 2019 in HIV-negative populations (A, B and C) and HIV-positive populations (D, E and F). (A) Y2 axis for India, South Africa and BRICS, (B) Y2 axis for India and China, (C) relative proportion indicated the proportion of all-cause deaths that come from tuberculosis, (D) Y2 axis for South Africa, (E) Y2 axis for India and South Africa, and (F) Y2 axis for South Africa. We used two different scales to distinguish the developing trends of each country. High-income Asia Pacific countries included Japan, Republic of Korea, Singapore, Brunei Darussalam. ASMR: age-standardised mortality rate; Relative proportion: relative proportion to all communicable, maternal, neonatal, and nutritional diseases; BRICS: Brazil, Russia, India, China, and South Africa; TB: tuberculosis; HIV: human immunodeficiency virus.

Figure 2

Local drift with net drift values for tuberculosis mortality and sex difference in Brazil, Russia, India, China, and South Africa from 1990 and 2019 in HIV-negative populations (A, B and C) and HIV-positive populations (D, E and F). Net drift (dotted line) represents the overall annual percentage change, and local drift (continuous line) values represent annual percentage change in each age group. Values below 0 indicated reductions in tuberculosis mortality across the study period. We only included the individuals aged 15-69 years old among HIV-positive populations due to the small number of HIV-TB patients aged over 70 (D, E and F). TB: tuberculosis; HIV: human immunodeficiency virus.

Figure 3

Parameter estimates of age, period, and cohort effects on HIV-negative tuberculosis mortality rate and sex difference in Brazil, Russia, India, China, and South Africa from 1990 to 2019. (A), (B), (C) Y2 axis for India and South Africa; (G), (H), (I) Y2 axis for China. A, B, C, Fitted longitudinal age curves of tuberculosis mortality (per 100 000 person-years) and the corresponding 95% CIs. D, E, F, Relative risk of each period compared with the reference (2000–2004) adjusted for age and nonlinear cohort effects and the corresponding 95% CI. G, H, I, Relative risk of each cohort compared with the reference (cohort 1955–1959) adjusted for age and nonlinear period effects and the corresponding 95% CI. TB: tuberculosis; HIV: human immunodeficiency virus.

Figure 4

Parameter estimates of age, period, and cohort effects on HIV-positive tuberculosis mortality rate in Brazil, Russia, India, China, and South Africa from 1990 to 2019. (A), (B), (C), (G), (H), (I) Y2 axis for South Africa. A, B, C, Fitted longitudinal age curves of tuberculosis mortality (per 100 000 person-years) and the corresponding 95% CIs. D, E, F, Relative risk of each period compared with the reference (2000–2004) adjusted for age and nonlinear cohort effects and the corresponding 95% CI. G, H, I, Relative risk of each cohort compared with the reference (cohort 1955–1959) adjusted for age and nonlinear period effects and the corresponding 95% CI. TB: tuberculosis; HIV: human immunodeficiency virus.