RT Journal Article SR Electronic T1 Follow-up of infants hospitalized for bronchiolitis. Clinical factors that determine their evolution JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP PA4182 DO 10.1183/13993003.congress-2015.PA4182 VO 46 IS suppl 59 A1 Zepeda, Guillermo A1 Díaz, Patricia A1 Pinto, Ricardo A1 Gaggero, Aldo A1 Uasapud, Paola YR 2015 UL http://erj.ersjournals.com/content/46/suppl_59/PA4182.abstract AB Background: It has been linked respiratory viral infection in infancy with more likelihood of developing asthma and atopy. The aim of this ongoing study is to analyze the clinical markers of patients hospitalized for bronchiolitis that determine their evolution.Patients and methods: Previously healthy infants hospitalized by bronchiolitis during 2009-2011. We determined in the nasopharyngeal aspirate the viral etiology by qPCR. Clinical record at the hospitalization and clinical follow up at the age of 4-5 years. Results are expressed in medians, mean and range. Mann-Whitney nonparametric statistical analysis.Results: 33 patients followed until now. The median age of hospitalization was 3.5 months. Etiology: respiratory syncytial virus (RSV) 49%, co-infection RSV and rhinovirus (RV) 33%, other viruses 18%. Of the total of patients,11(33%) are currently children with recurrent wheezing (RW). There was no difference between the RW group versus non RW group in: age of hospitalization; days of hospitalization, oxygen therapy, fever or cough; infection severity; personal or family atopy; presence of older siblings; or the single or dual infection. It stands out the high level of intradomiciliary contamination given by second-hand smoke (67%) and heating by combustion (70%) in the total of patients.Conclusions: The infection by RSV or co-infection of RSV and RV did not worsen the clinical evolution. The RW preschool children had no further development of atopy. The bronchial inflammation of our RW preschool children may be explained by other factors.Fondecyt 1120411 Project was approved by ethics committees of Roberto del Rio Hospital and Faculty of Medicine, University of Chile.