title: Acquisition of Streptococcus pneumoniae and nonspecific morbidity in infants and their families: a cohort study.
abstract: BACKGROUND
  Most children are believed to acquire Streptococcus pneumoniae asymptomatically, with only a few developing overt S. pneumoniae disease. This study investigates the relationship between acquisition of S. pneumoniae and mild nonspecific infection leading to general practitioner (GP) consultation.
  
  
  METHODS
  A prospective birth cohort study of 213 infants assessed at home 9 times during 24 weeks by nasopharyngeal swab and parental interview was conducted.
  
  
  RESULTS
  All positive S. pneumoniae swabs (including acquisition and carriage) were significantly associated with GP consultations for infection by the study infant compared with infants with negative swabs [odds ratio (OR), 1.6; 95% confidence interval (CI) 1.1-2.2; P = 0.005]. There was a stronger association with S. pneumoniae acquisition alone (OR 2.1; 95% CI 1.3-3.4; P = 0.001) than with carriage only (OR 1.4; 95% CI 0.9-2.0; P = 0.1). Multivariate analysis confirmed that S. pneumoniae acquisition by the study subject was independently associated with GP consultations: adjusted hazard ratio, 1.8 (95% CI 1.1-2.9); P = 0.02. A similar and independent association was found between S. pneumoniae acquisition by the study subject, and GP consultations for infection by the family (adjusted hazard ratio, 1.8; 95% CI 1.1-2.8; P = 0.01).
  
  
  CONCLUSIONS
  Acquisition of S. pneumoniae by the study infant was significantly associated with GP consultations for infection by the infant or family.
authors.affiliation: University Department of Paediatrics, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom.
authors.forename: Karen L
authors.initials: KL
authors.lastname: Sleeman
authors.forename: Lesley
authors.initials: L
authors.lastname: Daniels
authors.forename: Marion
authors.initials: M
authors.lastname: Gardiner
authors.forename: David
authors.initials: D
authors.lastname: Griffiths
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Deeks
authors.forename: Ron
authors.initials: R
authors.lastname: Dagan
authors.forename: Sunetra
authors.initials: S
authors.lastname: Gupta
authors.forename: E Richard
authors.initials: ER
authors.lastname: Moxon
authors.forename: Tim E
authors.initials: TE
authors.lastname: Peto
authors.forename: Derrick W
authors.initials: DW
authors.lastname: Crook
mesh_terms: D002353:Carrier State / Q000453:epidemiology*; D005260:Female; D006296:Health Services / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000635:transmission*; D011446:Prospective Studies; D012307:Risk Factors; D013296:Streptococcus pneumoniae / Q000302:isolation & purification