OBJECTIVES: Compare the clinical impact of respiratory syncytial virus (RSV) infection in adult patients and influenza viruses (IV) between 2017 and 2020.

METHODS: A retrospective research was carried out at the University Hospital of Guadalajara, Spain. Collected respiratory samples were tested using antigenic detection and real-time polymerase chain reaction. All patients with a positive result performed in the hospital were included and we review electronic medical records to collect all information.

RESULTS: 154 patients diagnosed with RSV and 526 with influenza viruses were included. Overall, the diagnosis of the infection motivated admission to a greater extent in patients infected with RSV (94%) vs IV (81.9%) (OR, 3.7; 95%CI 1.8-7.8; P < 0.001). Average hospital stay was longer in those patients infected with RSV (22.9 days) vs IV (15.1 days) (P = 0.217). The use of antibiotic therapy was statistically higher in patients infected by RSV compared to those IV (OR, 4.30; 95%CI 2.25-8.20; P < 0.001). The probability of readmission during the first month was greater in those patients infected with RSV: 16.7% vs IV: 10.25% (OR, 1.76; 95%CI 1.01-3.10; P = 0.046). There were more deaths in patients infected with RSV: 27.7% than with IV: 18,2% (OR 1.7; 95%CI 1.1-2.6) although after multivariante logistic analysis adjusted by sex, age and respiratory disease this differences were not statistically significant (OR 0.86; 95%CI 0.54-1.38; P = 0.5411).

CONCLUSIONS: VRS carries a significant cost due to a high likelihood of admission, consumption of antibiotics, long mean length stay, readmission and death.