16 RISK FACTORS LEADING TO SEVERE RESPIRATORY SYNCYTIAL VIRUS INFECTION IN FULL-TERM INFANTS

Prematurity, chronic lung disease, and congenital heart disease have been identified as risk factors for severe respiratory syncytial virus (RSV) infection and hospitalization.ObjectiveTo characterize additional risk factors that lead to severe RSV infection in infants > 36 weeks gestation.MethodsThe medical records of all children less than 2 years of age hospitalized for RSV infection during 2 RSV seasons (2003-2004 and 2004-2005) were reviewed. The data recorded included age, length of hospital stay, intensive care unit (PICU) stay, and oxygen and ventilation requirement. Any risk factors that may have led to hospitalization or more severe disease were recorded.ResultsA total of 106 infants > 35 weeks' gestation were identified. The table below summarizes severity of RSV infections according to some of the risk factors that were identified: Underlying diseases included those with congenital anomalies, Down syndrome, and neuromuscular disease. Ten patients had overlapping risk factors (ie, some had asthma as well as tobacco exposure).ConclusionsAlthough having school-aged siblings predisposed to a higher frequency of RSV hospitalizations, having an underlying disease, such as Down syndrome or congenital heart disease, predisposed to a more severe course of RSV hospitalization as indicated by the much longer length of hospital and PICU stay. Patients exposed to passive smoking appear to have the mildest hospitalization course with virtually no PICU admission. Interestingly, patients with reactive airway disease were much older and also tended to have a milder hospitalization course. In general, patients with no risk factors for RSV infection were much younger than the others and had a more severe RSV course. The 10 patients with multiple risk factors did not have a worse hospital course compared with those with a single risk factor.