title: Impact of home environment interventions on the risk of influenza-associated ARI in Andean children: observations from a prospective household-based cohort study.
abstract: BACKGROUND
  The Respiratory Infections in Andean Peruvian Children (RESPIRA-PERU) study enrolled children who participated in a community-cluster randomized trial of improved stoves, solar water disinfection, and kitchen sinks (IHIP trial) and children from additional Andean households. We quantified the burden of influenza-associated acute respiratory illness (ARI) in this household-based cohort.
  
  
  METHODS
  From May 2009 to September 2011, we conducted active weekly ARI surveillance in 892 children age <3 years, of whom 272 (30.5%) had participated in the IHIP trial. We collected nasal swabs during ARI, tested for influenza and other respiratory viruses by RT-PCR, and determined influenza incidence and risk factors using mixed-effects regression models.
  
  
  RESULTS
  The overall incidence of influenza-associated ARI was 36.6/100 child-years; incidence of influenza A, B, and C was 20.5, 8.7, and 5.2/100 child-years, respectively. Influenza C was associated with fewer days of subjective fever (median 1 vs. 2) and malaise (median 0 vs. 2) compared to influenza A. Non-influenza ARI also resulted in fewer days of fever and malaise, and fewer healthcare visits than influenza A-associated ARI. Influenza incidence varied by calendar year (80% occurred in the 2010 season) and IHIP trial participation. Among households that participated in the IHIP trial, influenza-associated ARI incidence was significantly lower in intervention than in control households (RR 0.40, 95% CI: 0.20-0.82).
  
  
  CONCLUSIONS
  Influenza burden is high among Andean children. ARI associated with influenza A and B had longer symptom duration and higher healthcare utilization than influenza C-associated ARI or non-influenza ARI. Environmental community interventions may reduce influenza morbidity.
authors.affiliation: Division of Infectious Diseases, Department of Internal Medicine, Vanderbilt University, Nashville, Tennessee, United States of America.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Budge
authors.affiliation: Department of Health Policy, Vanderbilt University, Nashville, Tennessee, United States of America.
authors.forename: Marie R
authors.initials: MR
authors.lastname: Griffin
authors.affiliation: Vanderbilt Vaccine Research Program, Division of Infectious Diseases, Department of Pediatrics, Vanderbilt University, Nashville, Tennessee, United States of America; Department of Pediatrics, Vanderbilt University, Nashville, Tennessee, United States of America.
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Edwards
authors.affiliation: Department of Pediatrics, Vanderbilt University, Nashville, Tennessee, United States of America; Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, Tennessee, United States of America.
authors.forename: John V
authors.initials: JV
authors.lastname: Williams
authors.affiliation: Instituto de Investigación Nutricional, Lima, Peru.
authors.forename: Hector
authors.initials: H
authors.lastname: Verastegui
authors.affiliation: Instituto de Investigación Nutricional, Lima, Peru; Swiss Tropical and Public Health Institute, and University of Basel, Basel, Switzerland.
authors.forename: Stella M
authors.initials: SM
authors.lastname: Hartinger
authors.affiliation: Swiss Tropical and Public Health Institute, and University of Basel, Basel, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Mäusezahl
authors.affiliation: Department of Pediatrics, Vanderbilt University, Nashville, Tennessee, United States of America.
authors.forename: Monika
authors.initials: M
authors.lastname: Johnson
authors.affiliation: Department of Pediatrics, Vanderbilt University, Nashville, Tennessee, United States of America.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Klemenc
authors.affiliation: Department of Biostatistics, Vanderbilt University, Nashville, Tennessee, United States of America.
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Instituto de Investigación Nutricional, Lima, Peru.
authors.forename: Ana I
authors.initials: AI
authors.lastname: Gil
authors.affiliation: Instituto de Investigación Nutricional, Lima, Peru.
authors.forename: Claudio F
authors.initials: CF
authors.lastname: Lanata
authors.affiliation: Department of Health Policy, Vanderbilt University, Nashville, Tennessee, United States of America.
authors.forename: Carlos G
authors.initials: CG
authors.lastname: Grigalva
mesh_terms: D000208:Acute Disease; D015331:Cohort Studies; D004777:Environment; D005260:Female; D006798:Housing / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D009975:Orthomyxoviridae / Q000502:physiology*; D010568:Peru / Q000453:epidemiology; D011446:Prospective Studies; D012140:Respiratory Tract Diseases / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology*; D012307:Risk Factors