RT Journal Article SR Electronic T1 Bronchiolitis from RSV (NA1, ON1 and BA) and recurrent wheezing over 3 years follow-up JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP PA5000 DO 10.1183/13993003.congress-2019.PA5000 VO 54 IS suppl 63 A1 Raffaella Nenna A1 Antonella Frassanito A1 Laura Petrarca A1 Greta Di Mattia A1 Marianna Di Martino A1 Domenico La Regina A1 Elio Iovine A1 Cristina Latini A1 Agnese Viscido A1 Carolina Scagnolari A1 Alessandra Pierangeli A1 Fabio Midulla YR 2019 UL http://erj.ersjournals.com/content/54/suppl_63/PA5000.abstract AB Rationale: We aimed to study wheezing recurrence after bronchiolitis from different RSV genotypes: RSVA NA1 and ON1, and RSVB BA.Methods: We prospectively enrolled term infants < 1 year, hospitalized with bronchiolitis over 12 epidemics. In RSV-positive nasopharyngeal washings, the viruses were genotyped and most were also quantified to obtain strain-specific viral loads. Clinical data were registered with a structured questionnaire and a clinical severity score was assigned to all infants at hospital admission. Every 12 months after discharge, we interviewed parents of infants seeking information on recurrent wheezing (≥2 physician verified episodes of wheezing/year).Results: 125 infants had NA1, 49 ON1, and 41 BA bronchiolitis. At 3 years, we registered wheezing in 65.6% NA1, 77.6% ON1 and 75.6% BA bronchiolitis children. Patients with wheezing had a higher RSV load when hospitalized with bronchiolitis (6.3±1.6 vs 5.6±1.5; p=0.015 copies/ml), particularly in ON1 infants (7.3±1.1vs 6.3±1.3; p=0.026). Among NA1 infants, wheezing was more frequent in children who had a severe bronchiolitis comparing to those children who had a mild bronchiolitis (75.9% vs 56.7%; p=0.025). The logistic regression analysis adjusted for sex, family history of asthma, passive smoking exposure, RSV genotype and eosinophils count, found severe bronchiolitis (OR: 2.9; 95% CI: 1.3, 6.6; p=0.01) and high viral load (OR:1.3; 95% CI: 1.0, 1.6; p=0.04) as risk factors for wheezing at 3 years.Conclusion: Viral factors (genotype specific-viral load) and clinical factors (severity score) contribute to the occurrence of respiratory sequelae after hospitalization for RSV sole bronchiolitis.FootnotesCite this article as: European Respiratory Journal 2019; 54: Suppl. 63, PA5000.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).