title: Influenza-like Illness in Households with Children of Preschool Age.
abstract: BACKGROUND
  Influenza-like illness (ILI) is the leading cause of medical consultation amongst preschool children, who may contribute to spreading ILI-causing agents within the household. We aimed to determine the societal burden (incidence, health-care consumption and productivity loss) and correlates of ILI in households with preschool children.
  
  
  METHODS
  A survey was performed in the Netherlands during October 2012 to October 2014. Monthly, 2000 households with children younger than 4 years were invited to report their symptoms and related medical care, productivity loss and putative risk exposures for 1 preschool child and 1 parent.
  
  
  RESULTS
  Eight thousand seven hundred and sixty-eight child-parent pairs were enrolled. ILI incidence was 2.81 episodes/child-year and 1.72 episodes/parent-year. Amongst those with ILI, health-care utilization was 35.7% (children) and 17.7% (parents). Work absenteeism was 45.7% (median 2 workdays lost) and day-care absenteeism was 22.8% (median 1 day missed). Chronic respiratory conditions, developmental disabilities, parental occupation in health care/child care, having a sibling and attending day care for ≤12 months increased childhood ILI risk. Parental ILI risk increased with having chronic respiratory conditions, developmentally disabled day-care-attending children and female gender in interaction with unemployment and multiple day-care-attending children. Breastfeeding infants 6-month-old or younger and attending day care for >24 months decreased childhood ILI risk. Pregnancy, occupation in health care and having ≥3 children decreased parental ILI risk. Parents of ILI-affected children had a concurrent 4-fold higher ILI risk.
  
  
  CONCLUSIONS
  ILI in households with preschool children has a considerable societal impact. Risk-mitigating initiatives seem justified for day-care attendees, mothers, people with chronic respiratory conditions, and children with developmental disabilities. Children attending day care for >2 years acquire some protection to ILI.
authors.affiliation: From the *National Institute for Public Health and the Environment (RIVM), Centre for Infectious Disease Control (CIb), Bilthoven, the Netherlands; †Department of Infectious Diseases and Immunology, Utrecht University, Utrecht, the Netherlands; and ‡Department of Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Lapo
authors.initials: L
authors.lastname: Mughini-Gras
authors.forename: Roan
authors.initials: R
authors.lastname: Pijnacker
authors.forename: Remko
authors.initials: R
authors.lastname: Enserink
authors.forename: Moniek
authors.initials: M
authors.lastname: Heusinkveld
authors.forename: Wim
authors.initials: W
authors.lastname: van der Hoek
authors.forename: Wilfrid
authors.initials: W
authors.lastname: van Pelt
mesh_terms: D000293:Adolescent; D000328:Adult; D002675:Child, Preschool; D017281:Cost of Illness; D003430:Cross-Sectional Studies; D005191:Family Characteristics; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007251:Influenza, Human / Q000453:epidemiology*; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D010342:Patient Acceptance of Health Care; D012307:Risk Factors; D014777:Virus Diseases / Q000453:epidemiology*; D055815:Young Adult