Incidence and risk factors of respiratory syncytial virus-related hospitalizations in premature infants in Germany

Premature infants have an increased risk of developing complicated respiratory syncytial virus (RSV) infections. Epidemiological data on RSV-related hospitalizations are a prerequisite to develop guidelines for the use of preventive measures. The objective of this study was to determine incidence and risk factors of RSV-related rehospitalizations (RSV-RH) of premature infants. We recruited 1, 103 infants with a gestational age of less than 35 weeks. primarily admitted to nine neonatologic care units in southern Germany between Nov. 1. 1998 and Oct. 31, 1999. Questionnaires were sent to all parents of infants discharged from neonatal care units to determine the risk of rehospitalization for acute respiratory infections (ARI-RH) and RSV-RH in the 1999-2006 season. The questionnaire response rate was 68.4%. The 717 included infants of the responders had a mean gestational age of 31.6 weeks (Range: 23-35) and a mean birth weight of 1.747 g (range: 430-4,050 g). The risk for an ARI-RH was 10.6% and the risk for RSV-RH 5.2% during the observation period. Premature infants with chronic lung disease (CLD) had a probability of 24.5% for ARI-RH and or 15% for RSV-RH. The following Factors were independently associated with an increased risk of RSV-RH: male gender (adjusted Odds-Ratio (OR): 8.7: 95% confidence interval (Cl): 2.6-29.1). chronic lung disease (OR: 3.99: 95%Cl: 1.4-11.2), discharge between October and December (OR: 2.1; 95%Cl: 0.99-4.4). day-care attendance of siblings (OR: 3.9, 95%Cl: 1.9-8.3). Conclusions: The risk for RSV rehospitalization among premature infants discharged from neonatal care facilities in southern Germany was low. Additional risk factors and high costs of prophylaxis have to be considered when infants are selected for RSV prophylaxis using monoclonal antibodies.