Respiratory disorders and hospitalization rates during the second RSV season in preterm infants who received palivizumab prophylaxis during their first RSV season

This prospective study evaluated the frequency and severity of respiratory symptoms during the second respiratory syncytial virus (RSV) season in an Italian cohort of preterm infants (≤35 weeks) who had received palivizumab prophylaxis in their first year of life (October 2004-April 2005) and who had not previously been hospitalized for RSV-induced lower respiratory tract infection (LRTI). Infants were evaluated at enrolment (May-September 2005), in October/November 2005 and in April 2006. The occurrence of any respiratory episode, the rate of hospitalization for respiratory-related LRTI, total length of stay in hospital, physician-documented recurrent wheezing (≥3 physician-documented episodes of wheezing) and use of airway medication/antibiotics were recorded during follow-up. All infants had prior palivizumab prophylaxis during their first RSV season. In the total evaluable population (n=260), 32.3% of infants experienced at least one respiratory episode, 3.8% required short hospitalization because of LRTI, 8.5% had physician-documented recurrent wheezing, and 48.8% required airway medications/antibiotics during follow-up. In this study the rate of airway morbidity, hospitalization and physician-documented recurrent wheezing during the second RSV season was low among preterm infants who had received prior palivizumab prophylaxis.