[Lower respiratory tract infection due to respiratory syncytial virus in hospitalized adults].

INTRODUCTION: The low detection of respiratory syncytial virus (RSV) pneumonia in hospitalized adults favors hospital-acquired transmission (HI) and inappropriate use of resources. MATERIALS AND METHODS: Retrospective observational study of patients hospitalized between May and August 2024 over 18 years of age with a diagnosis of RSV pneumonia by nasopharyngeal swab polymerase chain reaction (PCR) test. RESULTS: A total of 88 patients were included, classified into four groups: pneumonia without etiological rescue (48/88), bacterial pneumonia (7/88), viral pneumonia (33/88). Positive RSV cases (18/33) made up the cohort of interest. The median age was 74 years (25-75th percentiles: 61-86), with a predominance of females and the presence of comorbidities, mainly cardiovascular (12/18) and chronic respiratory (6/18); 12/18 patients had IH infection. Most frequent symptoms: dyspnea (14/18), fever (13/18) and cough (10/18). In imaging studies, the alveolar pattern predominated (8/18), followed by the mixed pattern (4/18). Most received empirical antibiotic therapy (17/18); only 9 discontinued treatment after the viral etiology was confirmed. Five deaths were recorded, mostly women over 80 years of age with IH pneumonia, all secondary to acute respiratory failure. CONCLUSION: RSV pneumonia in hospitalized adults was associated with a high frequency of nosocomial transmission, antibiotic use despite viral diagnosis, and high mortality in people over 80 years of age with comorbidities. These findings underscore the need to strengthen prevention and surveillance strategies, along with the implementation of vaccination measures in vulnerable groups.