Frequency and Seasonal Variations of Viruses Causing Respiratory Tract Infections in Children Pre- and Post-COVID-19 Pandemic in Riyadh (2017-2022).

Introduction The COVID-19 pandemic has had a major impact on healthcare systems throughout the world. As the clinical and epidemiological features of COVID-19 share many similarities with other respiratory viruses in children, ensuring optimal management of different viral respiratory diseases is critical. The precautions taken to prevent COVID-19 have seemingly had an indirect effect on the seasonal variations of viral diseases and the frequency of relevant viruses. The seasonal irregularity of and uncertainty surrounding these infection peaks may affect the clinical prediction and management resources. Therefore, the aim of this study is to evaluate the impact of the COVID-19 pandemic on the frequency and seasonal variation of common respiratory viruses in children pre- and post-pandemic. Methodology This study utilizes a descriptive cross-sectional retrospective approach. A total of 726 samples collected from children below 14 years of age and admitted to King Abdulla bin Abdulaziz University Hospital between March 2017 and February 2022 were included in the present study to evaluate the impact of the COVID-19 pandemic on the frequency and seasonal variation of common respiratory viruses in children pre- and post-pandemic. The samples taken before March 15, 2020, were considered pre-COVID-19, and those taken from March 15, 2020, onward were considered post-COVID-19. The seasons were divided based on the months of the year as per the Saudi climate website (winter: December-February, spring: March-April, summer: May-August, and autumn: September-November). Results All nasopharyngeal swabs (NPS) for viral Polymerase chain reaction (PCR) multiplex that were done for all admitted children of age up to 14 years were included, and the total samples amounted to 726, There were 686 (94.4%) positive samples for viruses and 40 (5.5%) negative samples. The number of positive samples pre-COVID-19 pandemic was 494 (72%), and the number of positive samples post-COVID-19 pandemic was 192 (28%). The frequency of different viruses has decreased post-COVID-19 and seasonality has changed; Although Adenovirus, and influenza viruses have no big changes, but Human Rhino/enterovirus (HRE) has increased frequency post-COVID-19 (49%), while post-COVID-19 it was (29.1%). The seasonal peak for Respiratory Syncytial Virus (RSV) pre-COVID-19 showed mainly in winter (49%), while post-COVID-19 it showed no peak. Conclusion The frequency of most types of viruses is noted to be lesser in the post-COVID-19 period, most likely due to precautions followed during the pandemic. This is not the case for HRE which showed increasing frequency in post-COVID-19; However, there are clinically and statistically significant differences among seasonal peaks in Respiratory RSV, HRE, and Parainfluenza viruses (PIV) pre- and post-COVID-19 pandemic. RSV showed no peak in different seasons post-COVID-19, although its peak pre-COVID-19 was in winter and autumn; Additionally typical trend of HRE peak changed to be in Autumn and spring post-COVID-19 instead of winter pre-COVID-19.