title: Frequency of acute respiratory illnesses and circulation of respiratory viruses in households with children over 3 surveillance seasons.
abstract: BACKGROUND
  The household has traditionally been the site for studying acute respiratory illnesses (ARIs). Most studies were conducted many years ago, and more broadly sensitive laboratory methods to determine ARI etiology are now available.
  
  
  METHODS
  We recruited and followed households with children over 3 annual surveillance periods and collected respiratory tract specimens from subjects with reported ARI. Virus etiology was determined by real-time reverse-transcription polymerase chain reaction (RT-PCR) analysis.
  
  
  RESULTS
  Individuals in larger households (defined as households with >4 members) and those in households with children aged <5 years had significantly higher ARI frequencies than others. ARI frequency generally declined with increasing age. Virus etiology was most likely to be determined in young children, who were also most likely to have virus coinfection. Overall, 16% of ARIs with 1 virus identified had ≥1 coinfecting virus. Rhinoviruses and coronaviruses were the most frequently identified agents of ARI in all age categories. Influenza virus and adenovirus were less frequently identified but were most likely to cause ARI that required medical attention.
  
  
  CONCLUSIONS
  Longitudinal studies in families remain a valuable way to study respiratory infections. RT-PCR has increased the sensitivity of virus detection, including coinfecting viruses, and expanded our ability to detect viruses now known to cause ARI.
authors.affiliation: Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor.
authors.forename: Arnold S
authors.initials: AS
authors.lastname: Monto
authors.affiliation: Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor.
authors.forename: Ryan E
authors.initials: RE
authors.lastname: Malosh
authors.affiliation: Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor.
authors.forename: Joshua G
authors.initials: JG
authors.lastname: Petrie
authors.affiliation: Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Mark G
authors.initials: MG
authors.lastname: Thompson
authors.affiliation: Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor.
authors.forename: Suzanne E
authors.initials: SE
authors.lastname: Ohmit
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D062486:Public Health Surveillance; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000821:virology*; D012621:Seasons; D014777:Virus Diseases / Q000453:epidemiology*; D055815:Young Adult
keywords: acute respiratory illnesses; households with children; influenza; respiratory viruses; surveillance