Background and aims Respiratory Syncitial Virus (RSV) causes respiratory infections that may be severe, especially in one of the highest risk populations: Premature infants. Palivizumab has proven safe and efficacious in reducing hospitalisation rate for RSV induced bronchiolitis in preterm neonates.

This study aimed to evaluate in a Spanish cohort of late preterm infants the incidence and risk factors of hospitalisation for RSV bronchiolitis. Update the indication of RSV prophylaxis.

Methods Descriptive study. A cohort of late preterm infants born in a Spanish third level hospital (2010–2014) was enrolled. Medical records were reviewed. Risk factors for RSV infections were reviewed. Recommendations for inmunoprophylaxis issued by the Spanish Society of Neonatology 2010 were followed.

Results 887 late preterm infants were enrolled. 4,1% were hospitalised for RSV bronchiolitis, median age was 5 months old. According to the gestational age: 16% were 34 weekers (one RSV prophylaxis), 45% 35 weekers (three RSV prophylaxis), and 38% 36 weekers (one RSV prophylaxis).

The risk factors for RSV hospitalisation: 56% were born in RSV season, 48% had school age siblings, 54% were male gender. Anyone was exposed to passive cigarette smoke.

16% were admitted to ICU. All the hospitalised infants required oxygen at any time. No deaths were reported.

Conclusions Hospitalisation rate for RSV bronchiolitis in late preterm infants of our cohort was higher than the estimated one in overall population. RSV prophylaxis was not routinely scheduled to late preterm infants according to the Guidelines issued by the Spanish Society of Neonatology. Its risk scoring tool for prophylaxis can be used to identify infants at higher risk.