[Global burden and predicted trends of diarrheal disease in children under five from 1990 to 2021].

OBJECTIVES: To conduct a comprehensive analysis of the global burden of diarrheal diseases in children under 5 years. METHODS: The data from the Global Burden of Disease (GBD) 2021 were analyzed to assess the incidence, mortality rates and average annual percentage changes (AAPC) of diarrhea among children under 5 years across nations(regions) and GBD regions from 1990 to 2021 using joinpoint regression. Smoothed curve regression was employed to explore the correlation of diarrheal disease burden with the Social Development Index (SDI) and for analyzing the burden of specific diarrheal pathogens. The Slope and Concentration Indices quantified disparities across SDI levels and the future trend were projected by the Bayesian Age-Period-Cohort (BAPC) model. RESULTS: From 1990 to 2021, the global incidence (AAPC: -3.65) and mortality (AAPC: -5.15) rates of diarrheal diseases declined steadily in children below 5 years. In 2021, neonates (<28 days) were the most affected, with an incidence rate of 138 058.74 per 100 000 and a mortality rate of 251.14 per 100 000. Rotavirus was the leading cause of death. The incidence rate of diarrheal diseases was negatively correlated with SDI, and the Concentration Index decreased from -0.293 in 1990 to -0.314 in 2021 without a significant gender difference. The BAPC model suggested that the global incidence rate of diarrheal diseases tends to decrease progressively from 2022 to 2050, with a predicted rate of 23 448.04 per 100 000 for male and 29 932.59 per 100 000 for female by 2050. CONCLUSIONS: Despite the reduction in the global burden of diarrhea and the projection of its further decline, diarrheal diseases disproportionately affect neonates and low-SDI regions. While rotavirus remains the primary etiological agent worldwide, the predominant pathogens vary by nations (regions) and GBD regions, and strengthened interventions targeting vulnerable populations are needed.