title: Blood culture and bacteremia predictors in infants less than three months of age with fever without source.
abstract: OBJECTIVE
  (1) To assess the rate of bacteremia in febrile infants less than 3 months of age admitted to a pediatric emergency department at a tertiary hospital; (2) to describe the bacteria isolated; and (3) to analyze factors related to increased probability of having a positive blood culture.
  
  
  METHODS
  A retrospective, cross-sectional, 5-year descriptive study that includes all infants less than 3 months of age who presented with fever without source (FWS) and had a blood culture performed.
  
  
  RESULTS
  A blood culture was performed in 1018 (91.5%) of 1125 infants admitted, and a bacterial pathogen was grown in 23 (2.2%) of these; 8 were associated with a positive urine culture. The most frequently isolated pathogen was Escherichia coli (9), followed by Streptococcus pneumoniae (4). The risk factors detected by multivariate analysis were: (a) being classified as "not well-appearing" (12.5% vs. 1.8%; odds ratio: 8.37) and (b) leukocyturia and/or nitrituria in a urine dipstick test (5.6% vs. 1.6%; odds ratio: 3.73). C-reactive protein value was higher than white blood cell count and absolute neutrophil count in detecting bacteremia; a 70 g/L cut-off had a specificity of 93.8%, but sensitivity of only 69.6%.
  
  
  CONCLUSIONS
  A positive blood culture rate of 2.2% was found in infants less than 3 months of age with FWS. C-reactive protein, white blood cell count, and absolute neutrophil count were not good bacteremia predictors. We recommend obtaining a blood culture in infants less than 3 months of age with FWS, particularly those patients considered "not well-appearing" and those with leukocyturia and/or nitrituria.
authors.affiliation: From the Paediatric Emergency Department, Cruces Hospital, Plaza de Cruces s/n, Barakaldo, Spain. borja.gomezcortes@osakidetza.net
authors.forename: Borja
authors.initials: B
authors.lastname: Gómez
authors.forename: Santiago
authors.initials: S
authors.lastname: Mintegi
authors.forename: Javier
authors.initials: J
authors.lastname: Benito
authors.forename: Andere
authors.initials: A
authors.lastname: Egireun
authors.forename: Diego
authors.initials: D
authors.lastname: Garcia
authors.forename: Eider
authors.initials: E
authors.lastname: Astobiza
mesh_terms: D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology; D001419:Bacteria / Q000145:classification* / Q000302:isolation & purification*; D001769:Blood / Q000382:microbiology*; D002097:C-Reactive Protein / Q000032:analysis; D003430:Cross-Sectional Studies; D004636:Emergency Service, Hospital; D004926:Escherichia coli / Q000302:isolation & purification; D005260:Female; D005335:Fever of Unknown Origin / Q000209:etiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007958:Leukocyte Count; D008297:Male; D009504:Neutrophils; D015995:Prevalence; D012189:Retrospective Studies; D013296:Streptococcus pneumoniae / Q000302:isolation & purification
chemical_list: D002097:C-Reactive Protein