title: Symptomatic and asymptomatic respiratory viral infections in the first year of life: association with acute otitis media development.
abstract: BACKGROUND
  Sensitive diagnostic assays have increased the detection of viruses in asymptomatic individuals. The clinical significance of asymptomatic respiratory viral infection in infants is unknown.
  
  
  METHODS
  High-throughput, quantitative polymerase chain reaction assays were used to detect 13 common respiratory viruses from nasopharyngeal specimens collected during 2028 visits from 362 infants followed from near birth up to 12 months of age. Specimens were collected at monthly interval (months 1-6 and month 9) and during upper respiratory tract infection (URTI) episodes. Subjects were followed closely for acute otitis media (AOM) development.
  
  
  RESULTS
  Viruses were detected in 76% of 394 URTI specimens and 27% of asymptomatic monthly specimens. Rhinovirus was detected most often; multiple viruses were detected in 29% of the specimens. Generalized mixed-model analyses associated symptoms with increasing age and female sex; detection of respiratory syncytial virus (RSV), influenza, rhinovirus, metapneumovirus, and adenovirus was highly associated with symptoms. Increasing age was also associated with multiple virus detection. Overall, 403 asymptomatic viral infections in 237 infants were identified. Viral load was significantly higher in URTI specimens than asymptomatic specimens but did not differentiate cases of URTI with and without AOM complication. The rate of AOM complicating URTI was 27%; no AOM occurred following asymptomatic viral infections. AOM development was associated with increasing age and infection with RSV, rhinovirus, enterovirus, adenovirus, and bocavirus.
  
  
  CONCLUSIONS
  Compared to symptomatic infection, asymptomatic viral infection in infants is associated with young age, male sex, low viral load, specific viruses, and single virus detection. Asymptomatic viral infection did not result in AOM.
authors.affiliation: Departments of Pediatrics Pathology.
authors.forename: Tasnee
authors.initials: T
authors.lastname: Chonmaitree
authors.affiliation: Departments of Pediatrics.
authors.forename: Pedro
authors.initials: P
authors.lastname: Alvarez-Fernandez
authors.affiliation: Preventive Medicine and Community Health.
authors.forename: Kristofer
authors.initials: K
authors.lastname: Jennings
authors.affiliation: Departments of Pediatrics.
authors.forename: Rocio
authors.initials: R
authors.lastname: Trujillo
authors.affiliation: Departments of Pediatrics.
authors.forename: Tal
authors.initials: T
authors.lastname: Marom
authors.affiliation: Pathology.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Loeffelholz
authors.affiliation: Departments of Pediatrics.
authors.forename: Aaron L
authors.initials: AL
authors.lastname: Miller
authors.affiliation: Departments of Pediatrics.
authors.forename: David P
authors.initials: DP
authors.lastname: McCormick
authors.affiliation: Departments of Pediatrics.
authors.forename: Janak A
authors.initials: JA
authors.lastname: Patel
authors.affiliation: Departments of Pediatrics Microbiology and Immunology, University of Texas Medical Branch, Galveston.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Pyles
mesh_terms: D058070:Asymptomatic Diseases / Q000453:epidemiology; D005260:Female; D057166:High-Throughput Screening Assays; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D009305:Nasopharynx / Q000821:virology; D010033:Otitis Media / Q000453:epidemiology / Q000821:virology*; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000821:virology*; D014777:Virus Diseases / Q000453:epidemiology / Q000821:virology*; D014780:Viruses / Q000145:classification* / Q000302:isolation & purification*
keywords: acute otitis media; asymptomatic infection; common cold; respiratory viruses; rhinovirus