[Dynamic changes in epidemiology of common national notifiable infectious diseases among children in a single center in Beijing, 2016-2024].

Objective: This study aimed to analyze the epidemiologic trends of common nationally notifiable infectious diseases (NID) among children at a single center in Beijing from 2016 to 2024. Methods: A cross-sectional study. Demographic and clinical data were retrospectively collected from 156 006 pediatric patients diagnosed with NID and reported to the National Health Information Disease Prevention and Control Information System at the outpatient or inpatient departments of Beijing Children's Hospital, Capital Medical University, between January 2016 and December 2024. The study period was divided into 3 groups based on the implementation status of non-pharmaceutical interventions (NPI) associated with the SARS-CoV-2 pandemic: pre-NPI implementation (2016-2019), during NPI implementation (2020-2022), and post-NPI lifting (2023-2024). Between-group comparisons were conducted using the χ² test and the Kruskal-Wallis rank-sum test. Results: Among the 156 006 pediatric cases included in the analysis, 89 202 were male and 66 804 were female. The age was 4.8 (2.7, 7.2) years. No category A infectious diseases were reported. Category B infectious diseases accounted for 12 734 cases (8.2%), while category C infectious diseases accounted for 135 187 cases (86.7%). Following the implementation of NPI, the average annual number of reported cases decreased by 67.6% (1 036/1 532) for category B infectious diseases and by 48.7% (5 613/11 520) for category C infectious diseases. At the transmission route level, diseases transmitted via the fecal-oral route decreased by 79.7% (5 225/6 556), while airborne transmission diseases decreased by 27.0% (2 096/7 753). Before the implementation of the NPI, 57 352 cases were reported, with hand-foot-mouth disease (HFMD) accounting for 22 213 cases (38.7%), influenza for 19 680 cases (34.3%), and varicella for 5 134 cases (9.0%). During the NPI implementation period, 21 036 cases were reported; the three most common diseases were influenza 13 292 cases (63.2%), HFMD 2 006 cases (9.5%), and varicella 1 815 cases (8.6%). After the lifting of NPI, 77 618 cases were reported, among which influenza 64 871 cases (83.6%), HFMD 5 004 cases (6.4%) and SARS-CoV-2 infection 2 191 cases (2.8%). After the lifting of NPI, the age at onset for HFMD, varicella, scarlet fever, other infectious diarrheal diseases, and pertussis was significantly higher than that observed before NPI implementation (all P<0.001). Conclusion: The shifting spectrum of pediatric NID and age of susceptible populations highlight the importance of the need for sustained surveillance to guide prevention strategies and adjust public health preparedness.