title: Objectives, design and enrollment results from the Infant Susceptibility to Pulmonary Infections and Asthma Following RSV Exposure Study (INSPIRE).
abstract: BACKGROUND
  Respiratory syncytial virus (RSV) lower respiratory tract infection (LRI) during infancy has been consistently associated with an increased risk of childhood asthma. In addition, evidence supports that this relationship is causal. However, the mechanisms through which RSV contributes to asthma development are not understood. The INSPIRE (Infant Susceptibility to Pulmonary Infections and Asthma Following RSV Exposure) study objectives are to: 1) characterize the host phenotypic response to RSV infection in infancy and the risk of recurrent wheeze and asthma, 2) identify the immune response and lung injury patterns of RSV infection that are associated with the development of early childhood wheezing illness and asthma, and 3) determine the contribution of specific RSV strains to early childhood wheezing and asthma development. This article describes the INSPIRE study, including study aims, design, recruitment results, and enrolled population characteristics.
  
  
  METHODS
  The cohort is a population based longitudinal birth cohort of term healthy infants enrolled during the first months of life over a two year period. Respiratory infection surveillance was conducted from November to March of the first year of life, through surveys administered every two weeks. In-person illness visits were conducted if infants met pre-specified criteria for a respiratory illness visit. Infants will be followed annually to ages 3-4 years for assessment of the primary endpoint: wheezing illness. Nasal, urine, stool and blood samples were collected at various time points throughout the study for measurements of host and viral factors that predict wheezing illness. Nested case-control studies will additionally be used to address other primary and secondary hypotheses.
  
  
  CONCLUSIONS
  In the INSPIRE study, 1952 infants (48% female) were enrolled during the two enrollment years and follow-up will continue through 2016. The mean age of enrollment was 60 days. During winter viral season, more than 14,000 surveillance surveys were carried out resulting in 2,103 respiratory illness visits on 1189 infants. First year follow-up has been completed on over 95% percent of participants from the first year of enrollment. With ongoing follow-up for wheezing and childhood asthma outcomes, the INSPIRE study will advance our understanding of the complex causal relationship between RSV infection and early childhood wheezing and asthma.
authors.affiliation: Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA. emma.larkin@vanderbilt.edu.
authors.forename: Emma K
authors.initials: EK
authors.lastname: Larkin
authors.affiliation: Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA. tebeb.gebretsadik@vanderbilt.edu.
authors.forename: Tebeb
authors.initials: T
authors.lastname: Gebretsadik
authors.affiliation: Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA. mlmoor2@emory.edu.
authors.forename: Martin L
authors.initials: ML
authors.lastname: Moore
authors.affiliation: Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA. larry.anderson@emory.edu.
authors.forename: Larry J
authors.initials: LJ
authors.lastname: Anderson
authors.affiliation: Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA. william.dupont@vanderbilt.edu.
authors.forename: William D
authors.initials: WD
authors.lastname: Dupont
authors.affiliation: Department of Pathology, Vanderbilt University Medical Center, Nashville, TN, USA. jim.chappell@Vanderbilt.edu.
authors.forename: James D
authors.initials: JD
authors.lastname: Chappell
authors.affiliation: Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA. patricia.minton@vanderbilt.edu.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Minton
authors.affiliation: Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA. stokes.peebles@vanderbilt.edu.
authors.forename: R Stokes
authors.initials: RS
authors.lastname: Peebles
authors.affiliation: Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA. paul.moore@vanderbilt.edu.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Moore
authors.affiliation: Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA. robert.valet@vanderbilt.edu.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Valet
authors.affiliation: Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA. don.arnold@vanderbilt.edu.
authors.forename: Donald H
authors.initials: DH
authors.lastname: Arnold
authors.affiliation: Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA. c.rosas.salazar@vanderbilt.edu.
authors.forename: Christian
authors.initials: C
authors.lastname: Rosas-Salazar
authors.affiliation: Virology Department, J. Craig Venter Institute, Rockville, MD, USA. sdas@jcvi.org.
authors.forename: Suman R
authors.initials: SR
authors.lastname: Das
authors.affiliation: Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA. fernando.p.polack@vanderbilt.edu.
authors.forename: Fernando P
authors.initials: FP
authors.lastname: Polack
authors.affiliation: Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA. tina.hartert@vanderbilt.edu.
authors.forename: Tina V
authors.initials: TV
authors.lastname: Hartert
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D004198:Disease Susceptibility; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015995:Prevalence; D011446:Prospective Studies; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology*; D012307:Risk Factors; D012720:Severity of Illness Index; D013714:Tennessee / Q000453:epidemiology