Dynamics of Hospitalization and Outcomes of Patients with COVID-19, Influenza, and Respiratory Syncytial Virus (RSV) in a Large Hospital

Purpose: Epidemiology data regarding coronavirus disease 2019 (COVID-19), influenza, and respiratory syncytial virus (RSV) in the Middle East is scarce. We describe hospitalization dynamics and outcomes across these viruses in hospitalized adults. Methods: A retrospective cohort study conducted in a 700-bed hospital in Israel. All hospitalized adults who tested positive for COVID-19, influenza, or RSV between 1 September 2023 and 31 August 2025 were included. Logistic regression models assessed variables associated with mortality. Results: Included were 2201 mono-infected adults (938 COVID-19, 1073 influenza, 190 RSV). COVID-19 demonstrated year-round distribution, whereas influenza and RSV showed seasonality. Invasive ventilation rates were 9.0%, 9.5% and 10.0% in COVID-19, influenza, and RSV patients, respectively. Rates of pneumonia after adjustment were more frequent with influenza. Unadjusted 30- and 90-day mortality were 17.3% and 22.7% for COVID-19, 10.7% and 13.1% for influenza and 18.4% and 21.6% for RSV. In multivariable models, virus type was not significantly associated with 30-day mortality, whereas age, male sex and Charlson comorbidity score were. Conclusions: Influenza and RSV exhibit distinct seasonality, whereas COVID-19 persists year-round, with periodic peaks. Mortality was substantial with all three viruses. These findings add to the understanding of respiratory viruses and support vaccination of older and comorbid adults against all three viruses.