Spatiotemporal variations of COVID-19, influenza, and respiratory syncytial virus (RSV) presentations to emergency departments in Alberta, Canada: A space-time retrospective population-based administrative data study

Simultaneous occurrence of respiratory viruses may stress medical services. The objective of this study was to identify time periods and geographic areas within Alberta, Canada that have excess numbers of patients presenting to emergency departments (EDs) with coronavirus disease 2019 (COVID-19), influenza, and respiratory syncytial virus (RSV). All ED presentations for the three viruses were extracted during April 2021 to March 2023. Retrospective space-time spatial scan statistics identified space-time clusters of COVID-19, influenza, and RSV individually and collectively. There were 74,277, 1,914, and 2,038 presentations for COVID-19, influenza, and RSV. In the early study period, presentations for influenza and RSV were nearly non-existent in the presence of large numbers of COVID-19. Presentations for COVID-19 declined in the second year whereas presentations for influenza and RSV increased. Collectively, COVID-19 dominated the ED presentations and four clusters were identified in the multivariate analyses. Three of the clusters also had elevated numbers of ED presentations for COVID-19 and RSV. Emergency presentations for the three common and concerning respiratory viruses varied by time, geography, and respiratory virus. “Twin-demic” clusters were identified for COVID-19 and RSV. These findings along with ongoing surveillance programs can help public health planning. NA.