The Burden of Acute Respiratory Infections on Emergency Departments: A Retrospective Study From a University Hospital in Central Italy.

Background and Aims: Acute respiratory infections (ARIs) have a relevant impact on public health in terms of prevalence and costs associated with the diseases. While the COVID-19 pandemic highlighted the need to adopt accurate surveillance systems to face new emergencies, the aim of our work is to describe ARIs other then COVID-19 and their impact on healthcare facilities. Methods: This retrospective study used an ecological approach to connect emergency department records and laboratory test results from a University Hospital in Italy. A time-series analysis has been performed to assess the association between weekly pathogen-specific positivity counts and ARI-related ED admissions. Results: During the study period, 33,101 ED presentations for ARI were registered, resulting in 7426 hospital admissions. ARI cases and viral diagnoses showed a seasonal peak during the late weeks of the year and early weeks of the following one. A reduction in ED admissions has been found in 2020, while the average weekly rate was 30.8% in 2020, as compared with 21.7% in 2017-2019. Analysis by age group showed a peak of accesses in the last weeks of 2021 for the < 1 and 1-4 years old. Conclusions: Data on ARI-related admissions highlight seasonal trends and age-related vulnerabilities, providing evidence to guide public health policies and support health system preparedness to respond to future epidemic waves.