[Epidemiological characteristics of respiratory syncytial virus among inpatients in a children's hospital in Shenzhen City from 2020 to 2023].

This study analyzed the epidemiological characteristics and trends of respiratory syncytial virus (RSV) infections among inpatients with acute respiratory infections (ARI) in a children's hospital in Shenzhen City inpatients from 2020 to 2023. From January 2020 to December 2023, multiple reverse transcription polymerase chain reaction (RT-PCR) combined with capillary electrophoresis fragment analysis technology was used to detect the nucleic acids of 12 respiratory pathogens, including RSV, in hospitalized children diagnosed with ARI. The patients were divided into six age groups: 0 to <6 months, 6 months to <1 year, 1 to <2 years, 2 to <5 years, 5 to <10 years, and 10 to <18 years. A total of 53 033 children were tested, including 6 830 RSV positive cases, with an overall positivity rate of 12.88%. The annual RSV positivity rates from 2020 to 2023 were 20.04%, 16.18%, 4.89%, and 13.33%, respectively, with statistically significant differences between the years (<i>χ²</i>=1 185.994, <i>P</i><0.001). The positive rate of RSV detection decreased with increasing age across all years (all <i>P</i> trend<0.05). From 2020 to 2023, the proportion of RSV-positive cases aged 2 to 5 years and older showed an increasing trend (<i>P</i> trend<0.001 for all years). Compared to 2023, the median age of RSV-infected children was lower in 2020 (<i>Z</i>=7.826, <i>P</i><0.001) and 2021 (<i>Z</i>=6.106, <i>P</i><0.001). The proportion of severe infections requiring ICU admission did not change significantly across all years (<i>χ²</i>=0.179, <i>P</i>=0.981). The RSV epidemic season in 2020 mainly occurred during 28-43 weeks, and in 2021, it spanned from 22-43 weeks. However, in 2022, the season was delayed until the 49th week and lasted for three weeks. In 2023, the seasonal epidemic appeared earlier, starting in the 14th week and lasting for 28 weeks. From 2020 to 2023, the rate of RSV co-infections with other pathogens (mycoplasma pneumoniae, human parainfluenza virus, human bocavirus, human coronavirus, human metapneumovirus, and influenza A) significantly increased (all <i>P</i> trend<0.01). In conclusion, the epidemiological characteristics of RSV infections in Shenzhen Children's Hospital changed from 2020 to 2023. In 2022, there were only delayed, low-intensity and short-lived seasonal epidemics. However, in 2023, there was an earlier and prolonged epidemic, with increased infections in children aged 2 to 5 years and older and a rise in co-infections, while the proportion of severe infections requiring ICU admission remained unchanged.