Age Distribution of RIDs

Major bacterial RIDs showed a statistically significant decreasing trend across all three age groups, with the steepest decline in children. Children's susceptibility to viral RIDs is explained by their incompletely developed immune systems, lower innate resistance, and frequent close contact in school settings. The bacterial RID burden shifted increasingly toward the elderly, with those aged 60 and above accounting for 57.87% of bacterial RID cases in 2023. The share of RID cases borne by children aged 0–14 increased across successive periods, rising from 39.58% in 2014–2018 to 52.61% in 2023. Children aged 0–14 consistently dominated viral RID cases, accounting for over two-thirds of cases from 2014 to 2022.