The Impact of COVID-19 Pandemic on Respiratory Syncytial Virus Infection in Children

Background/Objective: Respiratory syncytial virus (RSV) is a major cause of bronchiolitis in infants and young children. Bronchiolitis, an acute inflammation of the lower respiratory tract, can lead to pneumonia, respiratory failure, and death. We aimed to compare the incidence and severity of RSV infection in children aged 0-60 months before and during the coronavirus disease 2019 (COVID-19) pandemic. Methods: A retrospective chart review was conducted on patients aged 0-60 months who tested positive for RSV between May 1, 2018, and May 31, 2022, in a community hospital in Queens County, New York City, United States. Comparisons were made between seasons 2018-2019 and 2019-2020 as before, and seasons 2020-2021 and 2021-2022 as during the COVID-19 pandemic. Severity of RSV infection was assessed using the Bronchiolitis Severity Score (BSS). Data were analyzed using R software, a p value of < 0.05 was considered statistically significant. Results: The incidence of RSV infection in seasons 2018-2019 and 2019-2020 peaked from mid-October to February, whereas the first season during the COVID-19 pandemic (2020-2021) was truncated with a very low incidence of RSV infection, and season 2021-2022 peaked from September to January, with the highest incidence (37%) and lower frequency of RSV infection at any given point. Patients during the season 2021-2022 were older (H 2,196.6=12.5, p<0.001, 95% CI=5.4,25.6) and had milder illness (H 2,187.5=7.5, p<0.01, 95% CI=2.1,19.2). Conclusions: We observed a lower incidence of RSV infection and a lower rate of hospitalization for RSV during the COVID-19 pandemic. The second RSV season during the COVID-19 pandemic began earlier, lasted longer, and had a lower frequency. Older children with milder illnesses were affected most during this season. RSV epidemiology and disease burden were impacted by the COVID-19 pandemic and could have significant ramifications for its prevention and control strategies.