Abstract
OBJECTIVES: To investigate the long-term effects of non-pharmacological interventions (NPIs) measures on the epidemiological characteristics of common respiratory viruses in preschool children in Henan, China. METHODS: This was a retrospective observational study containing data from 17 prefecture-level cities in Henan, China. We analyzed and compared laboratory results and clinical data of preschool children presenting to outpatient clinics for acute respiratory infections (ARTI) after COVID-19 (January 2020-October 2022) and before COVID-19 (December 2017-December 2019). Each year was divided into quarters. The ratio of the odds ratios (ORs) of testing positive for eight respiratory viruses in each year after the pandemic to the prepandemic period was estimated applying a generalized linear model (GLM), using the mean of the positive detection rates in 2018-2019 as a reference. RESULTS: A total of 11,400 children were enrolled from December 2017 to October 2022. The number of positive detections for all respiratory viruses decreased in 2020-2022 compared to the average of 2018-2019. Human respiratory syncytial virus (hRSV), human rhinovirus (hRV), and influenza virus (IFV) accounted for a larger proportion of all detected viruses before COVID-19 pandemic, whereas hRV, human bocavirus (hBoV), and human adenovirus (hAdV) accounted for a significantly larger proportion after COVID-19 pandemic. The positive detection rates of enveloped viruses [IFV, human parainfluenza virus (hPIV), hRSV, human metapneumovirus (hMPV), and human coronavirus (hCoV)] decreased sharply and the seasonal activity of these viruses was weakened, while the positive detection rates of non-enveloped viruses (hRV, hBoV, and hAdV) increased, especially hRV. The conditions described above tended to occur more frequently in boys and children older than 1 year, and they were also more sensitive to the NPIs. CONCLUSIONS: NPIs transformed the epidemiological profile of common respiratory viruses among preschool children during the COVID-19 pandemic. To improve the overall public health response to all respiratory viruses, interventions targeting non-enveloped viruses need to be strengthened to mitigate their continued transmission.