Global Disability-Adjusted Life Years Burden of Lower Respiratory Infections Caused by Streptococcus pneumoniae, Staphylococcus aureus, and Klebsiella pneumoniae, 1990–2021: A Systematic Analysis of the Global Burden of Disease Study 2021

Abstract Background Streptococcus pneumoniae, Staphylococcus aureus, and Klebsiella pneumoniae are the principal pathogens responsible for fatalities due to lower respiratory infections (LRIs), which pose a significant global health burden. During 2020 and 2021, the COVID-19 pandemic substantially altered the pathogenic landscape of LRIs. However, the specific impacts on S. pneumoniae, S. aureus, and K. pneumoniae have yet to be clearly determined. This study aims to analyze the changes in disability-adjusted life years (DALYs) associated with LRIs caused by these pathogens from 1990–2021, with a particular focus on the effects of the COVID-19 pandemic. Methods We analyzed data on the DALY burden of LRIs attributable to S. pneumoniae, S. aureus, and K. pneumoniae from the Global Burden of Disease Study 2021, covering various geographic and demographic levels, including global, regional, national, age, and sex groups. To assess the overall trend, we calculated the estimated annual percentage change (EAPC) and used Joinpoint regression analysis to determine the annual percent change (APC) for local trends. Additionally, autoregressive integrated moving average (ARIMA) and Bayesian age-period-cohort (BAPC) models were utilized to forecast the age-standardized DALY rates (ASDRs) of the three pathogens through 2030. Results From 1990–2021, the ASDR for S. pneumoniae LRIs decreased the most significantly, dropping from 1249.50 per 100,000 population (95% UI: 1097.12–1415.86) in 1990 to 309.90 per 100,000 population (95% UI: 264.44–357.22) in 2021. In contrast, the ASDR for K. pneumoniae LRIs decreased from 281.51 per 100,000 population (95% UI: 242.56–321.31) in 1990 to 99.46 per 100,000 population (95% UI: 84.65–115.82) in 2021. S. aureus LRIs showed the slowest decline, with its ASDR decreasing from 242.89 per 100,000 population (95% UI: 216.69–270.69) in 1990 to 156.80 per 100,000 population (95% UI: 139.44–176.08) in 2021. East Asia experienced the most rapid decrease in the ASDR from 1990–2019 and was the only region with an increase during the COVID-19 pandemic (2019–2021). Pacific island nations, including Tokelau and Niue, experienced significant increases in ASDR during the pandemic. Vulnerable populations included children under five years of age and elderly individuals, with males facing a greater burden. Whereas the ASDR trends for S. pneumoniae LRIs and K. pneumoniae LRIs consistently declined, S. aureus LRI trends were irregular. The pandemic accelerated the reductions in ASDR for S. aureus LRIs and K. pneumoniae LRIs but slowed the decline in S. pneumoniae LRIs. By 2030, the ASDRs for these pathogens are projected to continue to decline, albeit at a slower pace for S. aureus LRIs. Conclusion Over the past 32 years, public health initiatives targeting LRIs caused by S. pneumoniae and K. pneumoniae have significantly progressed, demonstrating effective control and management strategies. In contrast, the management of S. aureus LRIs remains less effective, indicating a need for enhanced focus and resources. The recurrent and increasing impact of S. pneumoniae LRIs during seasonal epidemics and pandemics highlights the urgency of prioritizing this pathogen in public health strategies. Despite the rising threat, the potential of S. aureus to become a leading cause of LRI-related DALY burden is often overlooked, underscoring the critical need for increased public health investment. Additionally, the public health infrastructure in small island nations is particularly vulnerable, emphasizing the need for targeted improvements to bolster their crisis management capabilities.