Risk factors for respiratory syncytial virus bronchiolitis hospitalizations in children with chronic diseases

Background Respiratory syncytial virus (RSV) bronchiolitis is the most common lower respiratory tract disorder causing hospitalization in infants. Due to decreased hospitalization rates of premature infants following Palivizumab immune prophylaxis, the proportion of infants with chronic diseases not eligible for Palivizumab has increased. Aim To characterize infants hospitalized during 2014–2018 with RSV bronchiolitis, to compare between those with and without chronic conditions, and to identify risk factors for severe disease. Methods This retrospective study analyzed demographic and clinical data of patients younger than 2 years admitted with bronchiolitis during four consecutive RSV seasons. Results Of 1124 hospitalizations due to RSV bronchiolitis, 244 (22%) were in infants with chronic diseases. Although 20/1124 qualified for RSV prophylaxis, only eight received immune prophylaxis. Compared to otherwise healthy infants, children with chronic diseases had longer hospitalizations, median 4.8 days (interquartile range [IQR]: 3.4–8.3) versus 3.7 days (IQR: 2.7–5.1), p