Under-5 mortality of infectious diseases in 204 countries between 1990 and 2021

Infectious diseases account for nearly half of all under-5 deaths globally. Research on trends in total and specific infections remains limited. We aimed to comprehensively assess the under-5 mortality trends due to infections worldwide.

Data covering 38 infectious diseases were obtained from the Global Burden of Disease Study 2021. The estimated annual percentage change (EAPC) in under-5 mortality rate (U5MR) was calculated by gender, age, region, country and socio-demographic index (SDI). Bayesian age-period-cohort model was used to forecast future trajectories.

In 2021, infectious diseases caused 2.0 million under-5 deaths globally, with neonatal deaths accounting for 24.0%. The U5MR due to infections dropped 70% from 1,022.3 to 306.7 per 100,000 between 1990 and 2021. The neonatal infections mortality rate decreased relatively slowly by 58.7%, with an EAPC of -0.9% [95% confidence interval (CI): -1.0% to -0.8%] in neonatal sepsis and other infections, and -1.4% (95% CI: -1.6% to -1.2%) in non-HIV sexually transmitted infections. U5MR for most infectious diseases decreased with rising SDI. Notably, HIV/acquired immunodeficiency syndrome (AIDS) in South Asia, East Asia and Oceania, and dengue in high-income North America and Australasia exhibited upward trends. Disparities existed in infectious disease burden among nations, with South Sudan having the highest U5MR due to infections in 2021 (1,562.6 per 100,000). By 2050, the global U5MR due to infections was predicted to decrease to 174.5 per 100,000.

The overall burden of infectious diseases in children under 5 years of age has declined. Enhancing neonatal care is crucial for further reducing U5MR. Rising HIV/AIDS and tropical infections in certain regions require region-individualized strategies to achieve Sustainable Development Goals sooner.