Unraveling the Effects of the COVID-19 Pandemic on the Burden of Respiratory Syncytial Virus in a Tertiary Hospital in Catalonia, Spain: Season 2022-2023 Analysis (preprint)

Purpose: Respiratory Syncytial Virus (RSV) associated infections have historically been the cause of seasonal paediatric hospital departments’ saturation. During the COVID-19 pandemic, the community incidence of RSV was reduced, thus the hospital burden. The last RSV season broke out in early October 2022, 4-6 weeks earlier than in pre-pandemic years, and was thought to be the most demanding to date. Our aim was to assess the burden of RSV-related hospitalizations on a referral hospital (Catalonia, Spain) during the pre-pandemic years and the most recent 2022-2023 season. Methods: We analysed the paediatric hospital and intensive care (PICU) admissions data (January 2016 – January 2023) of a tertiary referral hospital in Catalonia, Spain. All-cause pediatric admissions, admissions related to confirmed RSV infections, and occupancy-related variables were collected. Results and conclusion: RSV-related hospitalizations incidence was lower during the pandemic years, particularly in 2020. The majority of RSV cases within an epidemic peak primarily affected children ≤3 months. Although the number of daily admissions during the last RSV 2022-2023 season was not higher than in the pre-pandemic years, the mean occupancy of the hospital was significantly higher (p= 0.04) due to a longer period of days with more than 20 RSV infected children inpatients per day.

Reduction of respiratory syncytial virus burden of disease observed in primary care diagnosis of children under 5 years old during the COVID-19 pandemic: a time-series analysis using routinely collected data from primary care electronic health records in Catalonia (Spain). (preprint)

Background: Great reductions of respiratory syncytial virus (RSV) in children were observed during the 2020 Southern hemisphere winter. Aim: To describe trends of RSV related disease in children in the Northern hemisphere and to propose a low cost clinical surveillance system based on primary care electronic health records (EHR). Methods: Time series analysis of RSV-related disease and virus laboratory-confirmations in children under 5 years old from 1 September 2009 to 16 January 2021. We collected RSV diagnoses from primary care EHR in Catalonia (Spain). We compared the trend of RSV in the season 2020-2021 with that in the previous seasons. We estimated the expected RSV cases with data from 2009 to 2018 using a time series regression adjusted by seasonality. We used the same method to estimate the expected RSV laboratory-confirmations as a sensitivity analysis. Results: In previous seasons, RSV-related disease peaks in Catalonia during the weeks 52 and 53. However in the 2020-2021 period, we observed a reduction of 87.6% (95% CI: 82.7% to 90.3%) in RSV-related disease from october 2020 compared to the expected. Only 1 RSV case was laboratory-confirmed during the 2020-2021 season until mid-January. Conclusions: We observed a nearly absence of RSV-related disease and laboratory-confirmations during the weeks when RSV usually peaks in Catalonia. The use of primary care EHR could be a low-cost surveillance system to monitorize trends of RSV the coming months.