Global epidemiological trends in the incidence and deaths of acute respiratory infections from 1990 to 2021

The aim of this study was to investigate the global epidemiological trends in the incidence and deaths of acute respiratory infections (ARIs), encompassing both upper respiratory infections (URIs) and lower respiratory infections (LRIs), from 1990 to 2021. Using data from the Global Burden of Disease study 2021 (GBD 2021), we utilized the average annual percentage change (AAPC) to examine the trends in the age-standardized incidence rate and deaths rate (ASIR and ASDRs) of URIs and LRIs. In 2021, the global ASIR of URIs and LRIs were 166,770.73 (95 % UI: 148,098.16-189,487.93) per 100,000 and 4283.61 (95 % UI: 4057.03-4524.89) per 100,000, respectively. The highest ASIR of URIs occurred in high-sociodemographic index (SDI) regions (232744.64, 95 % UI: 206887.07-261694.81) per 100,000, whereas LRIs occurred in low-SDI regions (9261.1, 95 % UI: 8741.61-9820.86) per 100,000. In 2021, the global ASDRs of URIs and LRIs were 0.28 (95 % UI: 0.09-0.61) per 100,000 and 28.67 (95 % UI: 25.92-31.07) per 100,000, respectively. The highest ASDRs of both URIs and LRIs were observed in low-SDI regions, with 1.1 (95 % UI: 0.08-2.78) per 100,000 and 70.68 (95 % UI: 62.56-78.62) per 100,000, respectively. From 1990 to 2021, the global ASIR for URIs and LRIs decreased, with AAPCs of -0.17 % (95 % CI: 0.17 % to -0.16 %) and -1.28 % (95 % CI: -1.37 % to -1.22 %), respectively. The global ASDRs also decreased (-3.39 % for URIs; -2.46 % for LRIs). However, during the COVID-19 pandemic, the ASIR of URIs increased in many countries, especially in high-SDI regions (rate difference before and during the COVID-19 pandemic in ASIR was 2210.19 per 100,000.) and low-SDI regions (rate difference in ASIR: 111.26 per 100,000). The global incidence and deaths related to ARIs have decreased over the past 32 years. However, it remains a significant public health concern, particularly due to the notable incidence of URIs in high SDI regions and the deaths associated with both URIs and LRIs in low SDI regions. Furthermore, an increase in the incidence of URIs was observed in both high- and low-SDI regions during the COVID-19 pandemic, highlighting the need for increased attention.