Respiratory syncytial virus infection in a Sicilian pediatric population: risk factors, epidemiology, and severity

Respiratory syncytial virus (RSV) is the leading cause of hospitalization for lower respiratory tract infections (LRTIs) in young children worldwide. This study evaluated the epidemiological and clinical patterns of RSV infection in infants hospitalized for LRTIs in Sicily. Over a 7-month period (October 1, 2005 to April 30, 2006), all children <2 years of age hospitalized for LRTIs were evaluated and tested for respiratory viruses. Logistic regression was used to identify the risk factors associated with RSV infection and with more severe disease. One hundred sixty-four children were enrolled and 40.9% were found to be RSV(+). The epidemic peak of RSV occurred in April, and no cases were observed in October, November, and December. RSV Infections had the highest incidence in children <3 months of age (54.7%). The likelihood to be RSV(+) rather than RSV(-) was lower for female gender and children >6 months old, with a gestational age (GA) of >36 weeks, with a birth weight of >2.50 g, with previous hospitalizations due to LRTI, with smokers in the household, and with a history of breast-feeding (p < 0.05 for each). RSV infection was associated with a higher likelihood to be admitted to neonatal intensive care units and to longer hospitalizations (p = 0.061). The collected data show that, in Sicily, RSV is an important cause of LRTIs in infants and a variety of factors, such as gender, chronological age at hospitalization, GA, birth weight, and exposure to tobacco smoke and breast-feeding may affect the prevalence of RSV-related lower respiratory tract disease and, possibly, the risk of developing asthma-like symptoms during the school years.