An analysis from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) highlights persistent health inequities in worldwide lower respiratory infection (LRI) burden, with the highest death rates in sub-Saharan African countries and in the youngest and oldest people.
LRIs, defined as pneumonia or bronchiolitis, are the world’s leading infectious cause of death, noted the authors, an international roster of scientists.
For the study, published yesterday in The Lancet Infectious Diseases, the team estimated rates of death from LRIs (pneumonia or bronchiolitis) and disability-adjusted life years (DALYs) and modelled case-fatality rates for 26 pathogens, including 11 newly modelled pathogens, from 204 countries and territories from 1990 to 2023.
The team measured progress toward the 2025 Global Action Plan for the Prevention and Control of Pneumonia and Diarrhoea (GAPPD) target of fewer than three deaths from pneumonia per 1,000 live births, or a death rate of fewer than 60 deaths per 100,000 preschoolers.
“With new data and revised modelling techniques, these estimates serve as an update and expansion to GBD 2021,” the researchers wrote.
Streptococcus pneumoniae caused largest share of deaths
In 1990, LRI deaths reached 2.97 million, and the all-age death rate was 55.7 per 100,000 people. In 2023, LRIs caused an estimated 2.5 million deaths and 98.7 million DALYs, with preschoolers and adults aged 70 years and older having the highest burden.
LRI deaths in preschoolers dropped 33.4% from 2010 to 2023, reaching a rate of 94.8 per 100,000 person-years. During the same period, death rates in adults aged 70 years and older fell 10.2%, but the burden remains substantial.
Of the 204 modeled countries, 129 achieved a death rate of fewer than 60 per 100,000 for preschoolers in 2023.
The total death rate in children younger than 5 years in sub-Saharan Africa was the furthest from the GAPPD target. Streptococcus pneumoniae continued to make up the largest number of LRI deaths globally (634,000 [25.3% of all LRI deaths]), followed by Staphylococcus aureus (271,000 [10.9%]), and Klebsiella pneumoniae (228,000 [9.1%]).
Among pathogens newly modelled in this study, non-tuberculous mycobacteria (responsible for 177,000 deaths) and Aspergillus spp (67,800 deaths) emerged as important contributors to LRI death. The 11 newly modelled pathogens together accounted for about 22% of LRI deaths.
Death rates in young kids still well above target
“This comprehensive analysis underscores both the gains achieved through vaccination and the challenges that remain in controlling the LRI burden globally,” the authors wrote. “Furthermore, it demonstrates persistent disparities in disease burden, with the highest mortality rates concentrated in countries in sub-Saharan Africa.”
Progress towards this target requires equitable access to vaccines and preventive therapies—including newer interventions such as respiratory syncytial virus monoclonal antibodies—and health systems capable of early diagnosis and treatment.
Around the world, the LRI death rate in preschoolers is still well above the GAPPD target.
“Progress towards this target requires equitable access to vaccines and preventive therapies—including newer interventions such as respiratory syncytial virus monoclonal antibodies—and health systems capable of early diagnosis and treatment,” the researchers wrote.
“Expanding surveillance of emerging pathogens, strengthening adult immunisation programmes, and combating vaccine hesitancy are also crucial. As the global population ages, the dual challenge of sustaining gains in child survival while addressing the rising vulnerability in older adults will shape future pneumonia control strategies.”
