title: Hospital admission due to respiratory viral infections in moderate preterm, late preterm and term infants during their first year of life.
abstract: BACKGROUND
  Respiratory viral infections are a major cause of hospitalisation in infants <1 year and might cause severe symptoms in preterm infants. Our aim was to analyse admissions due to respiratory infections in moderate, late and term infants, and to identify risk factors for hospitalisation in preterm versus term.
  
  
  METHODS
  Prospective study in a cohort of moderate and late preterm, and term infants born between October/2011 and December/2012. Admissions due to respiratory infections during the first year of life were analysed and compared among moderate (32-33), late (34-36) and term infants. Sixteen respiratory viruses were detected by RT-PCR. Clinical data were collected.
  
  
  RESULTS
  30 (20.9%) out of 143 preterm infants required admission for respiratory infection, versus 129 (6.9%) of 1858 term infants born in the same period (p<0.0001, OR: 3.6 CI 2.0 to 5.0). Hospitalised children had a higher prevalence of hyaline membrane disease (HMD) at birth (p<0.001, OR: 7.7 CI: 2.121 to 27.954) and needed more mechanical ventilation (p<0.001, OR: 5.7 CI: 1.813 to 18.396). Virus was identified in 25/30 (83%) preterm babies, and in 110/129 (85%) term infants. The most frequent viruses in preterm infants were RSV (76%) rhinovirus (20%). Clinical and epidemiological characteristics among term and preterm infants were similar.
  
  
  CONCLUSIONS
  The risk of respiratory admissions during the first year of life is up to 3.6 times higher in moderate and late preterm. Once admitted, clinical features of respiratory episodes requiring hospitalisation are similar among term and preterm infants. Hyaline membrane disease and mechanical ventilation were also risk factors for respiratory admissions.
authors.affiliation: Department of Neonatology and Department of Pediatrics, Severo Ochoa Hospital, Leganés, Madrid, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Olabarrieta
authors.affiliation: Department of Neonatology and Department of Pediatrics, Severo Ochoa Hospital, Leganés, Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Gonzalez-Carrasco
authors.affiliation: Department of Neonatology and Department of Pediatrics, Severo Ochoa Hospital, Leganés, Madrid, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Calvo
authors.affiliation: Influenza and Respiratory Viruses Laboratory, National Centre of Microbiology, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Pozo
authors.affiliation: Influenza and Respiratory Viruses Laboratory, National Centre of Microbiology, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Casas
authors.affiliation: Department of Neonatology and Department of Pediatrics, Severo Ochoa Hospital, Leganés, Madrid, Spain. Electronic address: marialuz.hso@gmail.com.
authors.forename: M L
authors.initials: ML
authors.lastname: García-García
mesh_terms: D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology / Q000628:therapy; D008297:Male; D011446:Prospective Studies; D012141:Respiratory Tract Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology / Q000628:therapy; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D047929:Term Birth; D014777:Virus Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology / Q000628:therapy
keywords: Late preterm; Moderate preterm; Respiratory viral infections