目的 了解新型冠状病毒肺炎（COVID-19）大流行前、中、后呼吸道合胞病毒（RSV）流行病学特征及其他病原体混合阳性情况，为完善儿童急性呼吸道感染（ARTIs）防治提供证据支持。方法 回顾性分析2016年1月至2024年5月在苏州大学附属儿童医院住院的≤16岁ARTIs患儿的病原体检测结果。分别比较COVID-19流行第一年（2020年，阶段Ⅰ）、第二和第三年（2021—2022年，阶段Ⅱ）、COVID-19流行后（2023 年1月至2024年5月，阶段Ⅲ）与疫情前期的RSV流行以及其他病原体混合阳性特征。结果 研究纳入83 356例ARTIs患儿，RSV阳性病例为11 277例（13.5%），单一RSV阳性5 605例（6.7%），RSV混合阳性5 672例（6.8%）。RSV阳性患儿中，细菌、其他病毒病原体、非典型病原体检出率分别为39.5%，13.6%和5.7%。与预测阳性率相比，2020年和2022年RSV检测阳性率有所下降，而2021年、2023年和2024年RSV检测阳性率有所上升。单一RSV阳性组与RSV混合阳性组之间年龄、流行时期和季节的分布差异均有统计学意义（P<0.001）；阶段Ⅲ期，RSV与其他病原混合阳性率显著高于单一RSV阳性率，差异有统计学意义（P<0.01）。RSV阳性患儿的甲/乙型流行性感冒病毒、副流感病毒、腺病毒、人偏肺病毒、肺炎支原体、肺炎衣原体和流感嗜血杆菌检出率明显升高。结论 COVID-19大流行对RSV流行及其他病原混合阳性的诊治产生不利影响，COVID-19流行后应长期监测RSV混合其他病原阳性的复发及感染升级。

Objective To understand the prevalence of respiratory syncytial virus (RSV) and co-positivity of other pathogens before, during and after COVID-19 pandemic, and to provide evidence-based support for improving the prevention and treatment of acute respiratory tract infections (ARTIs) in children. Methods The pathogen detection results of ARTIs children aged ≤16 years who were admitted to the Children's Hospital of Soochow University from January 2016 to May 2024 were retrospectively analyzed. The characteristics of RSV epidemics and mixed positivity for other pathogens in the first year of the COVID-19 epidemic (2020, Stage Ⅰ), the second and third years (2021-2022, Stage Ⅱ) and the post-COVID-19 epidemic (January 2023 to May 2024, Stage Ⅲ) were compared with those in the pre-epidemic period. Results The study included 83356 children with ARTIs, with 11277 (13.5%) testing positive for RSV, 5605 (6.7%) testing positive for RSV alone, and 5672 (6.8%) testing positive for RSV in combination with other respiratory pathogens. In RSV positive children, the detection rates of bacteria, other viral pathogens and atypical pathogens were 39.5%, 13.6% and 5.7%, respectively. RSV test positive rates decreased in 2020 and 2022, while RSV test positive rates increased in 2021, 2023 and 2024 compared with predicted positive rates. There were significant differences in age, epidemic period and season between single RSV positive group and mixed RSV positive group (P<0.001). In stage Ⅲ, the positive rate of RSV mixed with other pathogens was significantly higher than that of single RSV, and the difference was statistically significant (P<0.01). The detection rate of influenza A/B viruses, human parainfluenza virus, adenovirus, human metapneumovirus, Mycoplasma pneumoniae, Chlamydia pneumoniae and Haemophilus influenzae was significantly higher in children with RSV. Conclusions The COVID-19 pandemic had an adverse impact on the prevalence of RSV and the diagnosis and treatment of mixed-positive cases of other pathogens, and the resurgence of mixed-positive RSV and the escalation of infections should be monitored for a long time after COVID-19.