Changes in infant respiratory pathogens pre-during, and post-COVID-19 non-pharmacological interventions in Beijing
Authors: Han Tongying , Wang Yajuan , Zhang Di , Li Ying , Zhang Li , Yan Jin , Li Chi , Yang Shengnan , Guo Litao , Yan Huijuan 
Published: October 2024

Objective: To explore the effect of non-pharmacological interventions (NPIs) on respiratory pathogens among hospitalized infants aged 0–3 months in Beijing during the coronavirus disease 2019 (COVID-19) pandemic.
Method: Respiratory specimens were collected from 1184 infants aged 0–3 months. The infants were hospitalized at the Children's Hospital affiliated with the Capital Institute of Pediatrics from January 2018 to December 2023 for acute respiratory infections. Based on the outbreak of COVID-19 and the implementation and termination of NPIs, the data were divided into three groups: the pre-epidemic group (January 2018 to December 2019), the epidemic prevention and control group (January 2020 to December 2022), and the post-epidemic group (January 2023 to December 2023). The specimens were tested for 14 respiratory pathogens, including influenza virus A (Flu A), influenza virus B (Flu B), respiratory syncytial virus (RSV), parainfluenza virus (PIV), adenovirus (ADV), human metapneumovirus (HMPV), human bocavirus (HBV), human rhinovirus HRV, coronavirus (CoV), Chlamydia trachomatis (Ct), Chlamydia pneumoniae (C.pn), Mycoplasma pneumoniae (MP), Bordetella pertussis (BP), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
Result: A total of 1184 infants,including 649 men and 535 women,with acute respiratory infections were admitted. The positive detection rate for respiratory pathogens was 51.77% (N = 613). In 2023, the proportion of infants with respiratory infections after the epidemic was 19.4% (319/1646), the positive detection rate of respiratory pathogens was 68.3% (218/319), and the mixed infection detection rate of respiratory pathogens was 16.1% (35/218). Prior to the epidemic, these rates were 11.9% (431/3611), 37.1% (160/431), and 5.0% (8/160), respectively. During the epidemic prevention and control period, these rates significantly increased to 12.4% (434/3486), 54.1% (235/434), and 11.1% (26/235) (P<0.05), respectively. Post-epidemic, the proportion of newborns testing positive for respiratory pathogens decreased, whereas the number of infants aged 29–90 days significantly increased. The proportion of hospitalized weight and contact history with respiratory patients increased significantly compared to before and during the epidemic, with statistical significance (P<0.05). After the epidemic, a total of 13 respiratory pathogens were detected throughout the year. There were statistically significant differences in the detection rates of Flu A, PIV, SARS-COV-2, HRV, HMPV, ADV, and C.pn before, during, and after implementation of the NPI during the COVID-19 epidemic(P<0.05). Post-COVID-19 epidemic, the detection rates of Flu A, PIV, and SARS-COV-2 were significantly higher than those before and during the epidemic (P<0.017). The detection rates of HRV, HMPV, and ADV significantly increased after the epidemic compared to those before the epidemic (P<0.017). Before the COVID-19 epidemic, the positivity rate of respiratory pathogens was high in the first and fourth quarters. After the termination of NPIs, the positive detection rate decreased in the first quarter but increased in the second, third, and fourth quarters, with a statistically significant difference (P<0.05).
Conclusion: The implementation and lifting of COVID-19 NPIs have caused significant changes in the detection and seasonal distribution of respiratory pathogens in infants aged 0–3 months in Beijing. NPI temporarily reduced the detection rate of respiratory pathogens in infants during the prevalence of COVID-19. Understanding the prevalence of respiratory pathogens is particularly important for the prevention and control of respiratory diseases in infants.