Multidrug-resistant TB in children is rising: Urgent global action needed

Despite global efforts, multidrug-resistant tuberculosis in children is rising at an alarming rate, with younger children at the highest risk of mortality—urgent action is needed to reverse the trend.

Study: Global burden of multidrug-resistant tuberculosis in children and adolescents. Image Credit: Kateryna Kon / Shutterstock

In a recent study published in the journal Pediatric Research, researchers leveraged secondary datasets (specifically, the Global Burden of Disease 2019 database) to elucidate global trends in multidrug-resistant tuberculosis (MDR-TB) incidence and prevalence. Their study focused on children and adolescents (<20 years) between 1990 and 2019.

Their findings revealed that while MDR-TB incidence showed different trends over time, the overall estimated annual percentage change (EAPC) was 4.15% (95% uncertainty interval [UI]: 1.10–12.19%), with a sharp rise from 1990 to 2005, a slight decline from 2005 to 2015, and a resurgence from 2015 to 2019. Eastern Europe, Southern sub-Saharan Africa, and South Asia bore the most significant burden. Among affected children, females exhibited higher prevalence and incidence rates than males. Children below the age of five were found to be highly susceptible to MDR-TB-associated mortality (0.62 per 100,000 in 2019, the highest among all age groups) when compared with their older counterparts. These results highlight the need for extensive research and policy change to combat this growing disease and protect our children.

Background

Tuberculosis (TB) is a lung infection caused by the bacterium Mycobacterium tuberculosis. Multidrug-resistant tuberculosis (MDR-TB) is a type of tuberculosis resistant to both rifampicin and isoniazid, the two most common treatments for the infection. The disease is linked to previous TB infections and early stoppage of antibiotic treatment. MDR-TB prolongs infection duration, hampers treatment and recovery, and results in a significantly more severe prognosis, potentially resulting in mortality and a substantial economic burden to patients and their families.

Unfortunately, the global incidence of MDR-TB is rapidly rising – reports from 2014 estimate that ~3.5% of all TB cases were multidrug-resistant. Nations with high populations and low to low-medium socioeconomic status are the worst affected, with India, China, South Africa, and Russia accounting for more than 60% of confirmed cases.

“The World Health Organization launched the ‘End TB’ strategy in 2014 to achieve a 90% decline in TB incidence by 2035. To achieve this goal, it is essential to develop efficient strategies and increase the investment and commitment to MDR-TB control.”

Researchers speculate that children and adolescents are the most vulnerable age group to MDR-TB infections. Surprisingly, despite their known susceptibility, hitherto, no attempts have been made to estimate global trends in MDR-TB prevalence and incidence in this subpopulation.

About the study

The present study aims to elucidate global trends in MDR-TB incidence among children and adolescents (age = <20) to inform future research efforts and policy implementations better. Secondary study data was obtained from the Global Burden of Disease Study 2019 (GBD 2019), an extensive health database comprising epidemiology data from 369 nations, classified by age, sex, and sociodemographic regions.

“The latest GBD database (GBD 2019) has a user-friendly approach and provides data on various factors, such as all causes, risks, impairments, injuries, and mortality rates. Consequently, it has become a valuable resource for assessing and comparing disease burden across various countries and territories.”

Data of interest included annual incidence rates, disease prevalence, mortality rates, and disability-adjusted life years (DALYs) rates for the age group under investigation. Data from 1990 to 2019 were included in statistical analyses to establish annual trends. The statistical analyses comprised randomized Markov–Chain Monte-Carlo models to estimate disease burden trends, as well as estimated annual percentage change (EAPC) analyses to identify patterns in the dataset.

a MDR‐TB incidence rate in children and adolescents in 2019 in countries/territories; b EAPC of children and adolescents MDR‐TB incidence rate between 2010 and 2019 in countries/territories; c MDR‐TB death rate among children and adolescents afflicted with the disease in 2019. d EAPC of children and adolescents with MDR‐TB incidence rate between 2010 and 2019. e MDR‐TB DALY rate among children and adolescents in 2019. f EAPC of MDR‐TB DALYs rate among children and adolescents with the disease between 2010 and 2019. MDR‐TB multidrug-resistant tuberculosis; EAPC estimated annual percentage change; DALY disability-adjusted life year].

Study findings

Study findings revealed that in 2019 alone, an estimated 67,710.82 children and adolescents contracted MDR-TB, corresponding to 611,246.97 DALYs. Of these, 7,061.39 deaths occurred. Female children and adolescents were found to have higher prevalence and incidence rates than their male counterparts. Notably, younger children (<5 years) were the worst impacted, having substantially higher mortality and DALY rates than older children (15-19 years) despite the latter cohorts’ higher prevalence and incidence rates.

A more detailed examination of the global trend revealed three distinct phases: a sharp annual rise in novel MDR-TB incidence between 1990 and 2005, followed by a slight decline between 2005 and 2015, and a resurgence between 2015 and 2019. Mortality data, however, is promising – while 1990 to 2001 witnessed a five-fold increase in mortality rates (from 0.11 per 100,000 in 1990 to 0.55 per 100,000 in 2001), mortality has since declined to 0.27 per 100,000 in 2019.

Nation-specific analyses revealed that children and adolescents in Eastern Europe, Southern sub-Saharan Africa, and South Asia are the worst impacted, with an estimated 5.02, 12.95, and 5.01 cases per 100,000, respectively. Sociodemographic analyses revealed that lower SDI (sociodemographic index) regions, which include low- and low-middle-income countries, are more severely affected than well-to-do regions.

Conclusions

The present study is the first to elucidate the burden of MDR-TB in children and adolescents, thereby informing future researchers and policymakers of global and annual trends in this vulnerable age group. Study findings revealed that, overall, MDR-TB rates increased at an estimated annual percentage change (EAPC) of 4.15% (95% UI: 1.10–12.19%) between 1990 and 2019. Girls are more susceptible to infections than boys. However, older children (15–19 years) had a higher overall incidence rate, whereas younger children (<5 years) had the highest mortality rates.

Younger children, despite contracting the disease less often than their older counterparts, are far more vulnerable to severe infections and potential mortality. Additionally, the disease burden was found to be negatively correlated with the sociodemographic index (SDI), highlighting the disproportionate impact on low-income regions. Socioeconomically disadvantaged regions should be the focus of future research and policy implementation, given their disproportionately higher disease burden.