Pre‐admission virus detection during the COVID‐19 pandemic in children with and without symptoms of infection

Aim Pre‐admission viral screening is used only in exceptional situations such as pandemics. We therefore evaluated pre‐admission screening for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), respiratory syncytial virus (RSV) and influenza during the COVID‐19 pandemic, comparing epidemiology and clinical features of admitted children. Methods Children were screened at a paediatric emergency department from 1 March 2020 to 30 June 2022 by nasopharyngeal sampling and polymerase chain reaction kit. We retrospectively retrieved positive results from the laboratory and scrutinised charts of admitted children. Results Out of 15 927 screened children, 522, 127 and 572 were positive and admitted with RSV, influenza A or SARS‐CoV‐2, respectively. Of these, 29 (5.6%), 26 (24.1%) and 245 (44.8%) were incidental findings, lacking symptoms of infection. RSV and influenza A were initially absent but re‐emerged in the autumn of 2021. The rate of COVID‐19 rose when the Omicron variant emerged in December 2021. The median age of children with RSV was 0.3 years, of those with influenza A 6.7 years and of those with COVID‐19 1.6 years. Major complications were rare. Conclusion Frequent incidental detections of SARS‐CoV‐2 likely reflected widespread presence of a mild infection. Clinically, COVID‐19 was like other viral respiratory infections in children.