Incidence of RSV-related hospitalizations among elderly: a retrospective study from Italy

Abstract RSV is one of the most common causes of acute respiratory infections in both children and adults over 60. RSV can cause severe lower respiratory tract infections in older adults, leading to an increase of morbidity and mortality. The aim of this study was to assess the incidence of hospitalizations due to RSV infections in the Abruzzo region, Italy, among patients aged over 60 years. A retrospective study was performed in the Abruzzo region evaluating all admission performed during the years 2018-23. Data was collected from the hospital discharge records (HDRs), including all admissions occurred during the study period. Only admission of patients aged over 60 years were included. In the study were included only HDRs reporting specific ICD-9-CM codes: RSV acute bronchiolitis (466.11), RSV pneumonia (480.1), RSV positivity (079.6), acute unspecified bronchiolitis (466.19) and viral unspecified pneumonia (480.9). Based on the literature, roughly 9% of viral unspecified infections were attributed to RSV, so the RSV infection rate was estimated also for unspecified infections. Age and gender standardized hospitalization rates for RSV were estimated. The Joinpoint model was used to evaluate the trend estimating the average annual percent change (AAPC). In the study period, 42 (13.13%) RSV-related hospitalizations, 98 (30.63%) admissions for unspecified bronchiolitis and 180 (56.25%) for unspecified viral pneumonia were reported. An increasing trend was recorded, with an annual percentage change of + 14.81%. An increasing incidence was recorded between 2018 and 2020 (from 0.81 to 4.41), a subsequent decrease was highlighted from 2020 to 2022 (from 4.41 to 2.02), and a new increase was recorded in 2023 (3.60). The median length of hospital stay in patients with RSV was 11 days (IQR 6-18) and 4 patients (9.52%) died during the admission. This paper also confirmed increasing evidence that highlights the significant role of RSV in elderly patients. Key messages • An increasing trend was observed in admissions during the study period. • RSV represents a significant cause of admission among elderly.