Clinical features of RSV bronchiolitis in children during COVID-19 pandemic: a single centre study

Respiratory Syncytial Virus (RSV) remains a primary cause of acute respiratory infections in young children. The COVID-19 pandemic has reportedly altered the seasonality of RSV in various regions. This study aimed to describe the clinical features of RSV-associated acute bronchiolitis in children attending a secondary care hospital in Oman. It also studied the atypical shift in the RSV season in the COVID-19 pandemic with the absence of a winter peak. A retrospective descriptive cohort study was carried out at the secondary care facility Al Nahdha Hospital, Muscat, Oman over a period of two years (April 2020 to April 2022) A design was established to allow temporal analysis of changes in RSV seasonality and clinical outcomes during COVID-19. Out of 97 RSV-positive cases, the majority were infants aged six months or younger (72%, n = 70), with 87% born at term. A noticeable shift in RSV cases from the typical winter peak to the summer months was observed. Nearly half the cohort required respiratory support, with prematurity, asthma, and congenital heart disease (CHD) identified as common comorbidities. No significant relationship between RSV severity and co-infection with COVID-19 was found. RSV primarily affects younger infants, particularly those under six months of age. The study highlights a shift in RSV seasonality toward the summer months during the COVID-19 pandemic. These findings emphasize the importance of RSV prophylaxis for high-risk groups, including premature infants and those with CHD, within the studied population.