Changes in Epidemics of Respiratory Viral Infections Resulted From the COVID-19 Pandemic in Shanghai

To investigate the changing patterns of respiratory viral infections within the context of COVID-19 pandemic. The etiological surveillance data of eight respiratory viral pathogens among patients with ARIs in Shanghai between 2013 and 2023 were analyzed to evaluate the dynamic patterns of respiratory viral infections in Shanghai compared to global other regions during pre-pandemic (period 1), pandemic (period 2), and post-pandemic (period 3) periods of COVID-19. In Shanghai and various other global regions, there was a delay of 2‒4 months in the peak positive rate of IFV and a reverse seasonality for RSV, HMPV, and HBoV was observed following the relaxation of NPIs. The proportion of patients infected with any of these eight viruses experiencing fever or high fever notably increased. During the entire study period, IFV was consistently identified as the most prevalent virus, with IFV-B as the predominant stain during period 2, and IFV-A regained its dominance following the lifting of NPIs. The proportion of RSV among children significantly increased during period 2 compared to period 1. With the relaxation of NPIs, there has been a resurgence of certain viral pathogens, accompanied by notable alterations in seasonal patterns and the spectrum of viral pathogens.