Risk Factors for Severe Respiratory Syncytial Virus Infection in Hospitalized Children

Background: RSV often leads to hospitalization, and accurate knowledge of risk factors is crucial. Methods: We retrospectively analyzed laboratory-confirmed RSV hospitalizations regarding pregnancy factors, birth status, cigarette smoke exposure, nutrition, social conditions, clinical presentation, and severe disease defined as a need for passive oxygen therapy (pO2Tx), the presence of pneumonia, respiratory failure, intensive care unit (ICU) transfer, and prolonged hospitalization. Results: A univariate analysis included 594 children (median age 4 months) and revealed a pO2Tx relationship with age ≤ 3 months (OR = 1.56), prematurity (OR = 1.71), being born during RSV season (OR = 1.72), smoke exposure during pregnancy (both parents (OR = 2.41, father (OR = 1.8)), dyspnea (OR = 5.09), and presence of apnea (OR = 5.81). Pneumonia was associated with maternal smoke exposure (OR = 5.01), fever (OR = 3.92), dyspnea (OR = 1.62), history of aspiration (OR = 4.63), and inversely with age ≤ 3 months (OR = 0.45). Respiratory failure was associated with prematurity (OR = 3.13) and apnea (OR = 18.78), while the lower odds were associated with older age (OR = 0.57 per month) and presence of fever (OR = 0.11). ICU transfer was associated with apnea (OR = 17.18), but an inverse association was observed with age (OR = 0.54) and fever (OR = 0.11). A prolonged hospital stay was associated with prematurity (OR = 1.76), low birth weight (OR = 2.89), aspiration (OR = 4.93), and presence of fever (OR = 1.51). Conclusions: Age (up to 3 months), prematurity, and presence of apnea are risk factors for a severe RSV course.