In a recent study published in Lancet Infectious Diseasesresearchers assessed the global, national and regional burden and trends in tuberculosis.
Study: Age-specific global, regional and national progress towards the 2020 milestones of the WHO strategy to end tuberculosis: a systematic analysis for the Global Burden of Disease Study 2021. Image credit: SewCreamStudio/Shutterstock.com
Record
Tuberculosis is a major contributor to the global burden of disease despite being a preventable and treatable disease. It accounts for more than one million deaths each year, and in 2019, it was the leading cause of death from a single infectious agent. Global initiatives to address tuberculosis have been prominent since the 1990s.
The World Health Organization (WHO) End TB Strategy aims to accelerate progress by reducing TB incidence and deaths by 90% to 95% between 2015 and 2035.
Therefore, assessments of trends in the global burden of TB are necessary to assess progress towards these goals.
About the study
In the present study, researchers examined levels and trends in the global burden of tuberculosis and the attainment of age-specific incidence and mortality milestones. They used data from the Global Burden of Disease, Injury and Risk Factors Study 2021.
The team included data on vital registration, mortality surveillance, and minimally invasive tissue sample diagnoses of TB mortality in people without human immunodeficiency virus (HIV) co-infection.
Cause-of-death modeling generated estimates of mortality among HIV-naïve individuals by age, sex, location, and year. Furthermore, a population-attributable fraction approach was used to estimate age-related deaths among people with HIV.
In parallel, age-specific TB prevalence, incidence and mortality were modeled using Bayesian disease-type meta-regression. TB deaths attributable to risk factors were calculated.
In addition, the impact of the coronavirus disease 2019 (COVID-19) pandemic on mortality was assessed for countries with at least 10 TB deaths in 2019 for each age group.
TB incidence and mortality estimates were aggregated by HIV status and burden estimates for each form of TB were presented for five age groups – < 5, 5-14, 15-49, 50-69 and ≥ 70 years. Annual rates of change (ARC) specific to incidence and mortality were reported.
Foundings
Overall, 9.4 and 1.35 million TB cases and deaths occurred in 2021, respectively. Of these, cases of tuberculosis and HIV co-infection accounted for one million cases and 205,000 deaths. The age-standardized incidence and mortality rates were 115 and 16.2 per 100,000 population, respectively. These rates decreased by 37% and 61.1% between 1990 and 2021.
In 2021, 3.8% of cases and 4.5% of deaths were reported in under-fives, and 4.7% of cases and 1.5% of deaths occurred in the 5-14 age group. Most cases (54.9%) and deaths (36.4%) in 2021 occurred in the 15–49 age group.
In 2021, incidence rates exceeded 100 per 100,000 people in people aged five years and older in 34 countries and 5–14 years in 14 countries.
In addition, incidence rates exceeded 500 per 100,000 people in the age groups 15–49, 50–69, and ≥ 70 years in nine, 33, and 50 countries, respectively.
Mortality rates were greater than 25 per 100,000 people in the age groups < 5, 5–14 and 15–49 years in 20, 1 and 37 countries, respectively. Specifically, mortality rates above 300 per 100,000 people were observed in the age groups 50–69 and ≥ 70 years in eight and 44 countries, respectively.
ARCs in TB incidence were greatest in those aged <5 and 5–14 years between 2020 and 2021, falling by 4.1% and 3.7%, respectively, while reductions in adult age groups were around 2% .
In addition, the largest ARCs for mortality rates were observed in the same age groups. Central Asia and Central and Eastern Europe had the largest age-standardized ARCs between 2010 and 2021.
Globally, incidence rates of all ages decreased by 6.26% between 2015 and 2020, with a decrease of 4.9% in men and 7.9% in women. During the same period, global deaths from tuberculosis fell by 11.9%, with a greater change in women (13.8%). Global TB deaths fell to one million after controlling for the cumulative effects of risk factors (diabetes, smoking, and alcohol use).
Forty-one countries were included in the analysis of the impact of COVID-19. Accordingly, 50,900 TB deaths were expected in 2020 versus 45,500 observed deaths, representing 5,340 fewer deaths than expected.
Twenty countries continued to report data through 2021. In these countries, 39,600 deaths were expected versus 39,000 observed.
conclusions
The WHO’s first interim milestones for ending TB were not met in 2020, with only 6% and 12% reductions in incidence and mortality rates between 2015 and 2020, respectively.
There was different progress between age groups. people under 15 showed the steepest declines, while older groups had the smallest declines.
The final TB incidence and mortality milestones were achieved in 2020 by only 15 and 17 countries, respectively.
Audit programs should therefore assess these countries to explore the drivers of their progress. Furthermore, the impact of the COVID-19 pandemic has been heterogeneous and uncertain, which warrants additional data.
