title: Fever in the new millennium: a review of recent studies of markers of serious bacterial infection in febrile children.
abstract: OBJECTIVE
  Evaluation of a febrile infant or child for serious bacterial infections (SBI) can be a challenging task; there is no single reliable predictor of SBI in infants. This review examines some of the recent work evaluating the usefulness of indicators for SBI, such as white blood cell count (WBC), C-reactive protein (CRP), procalcitonin (PCT), and interleukin-6 (IL-6).
  
  
  RESULTS
  While WBC is traditionally used as an indicator of serious infection, it appears to be the least specific and sensitive test in children. CRP and PCT are the most promising, but neither is an ideal single indicator by itself, especially in infants. There has been very limited experience with PCT in this country, however. IL-6 is more useful than WBC but less accurate than either CRP or PCT.
  
  
  CONCLUSIONS
  Much progress has been made in recent years in finding more accurate indicators of SBI than WBC. However, while recent developments have given clinicians some new tools in evaluating febrile infants and children, it remains a formidable undertaking. In the especially vulnerable infant population, the holy grail of a single ideal SBI indicator remains elusive.
authors.affiliation: Division of Emergency Medicine, Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06520-8064, USA. allen.hsiao@yale.edu
authors.forename: Allen L
authors.initials: AL
authors.lastname: Hsiao
authors.forename: M Douglas
authors.initials: MD
authors.lastname: Baker
mesh_terms: D001424:Bacterial Infections / Q000097:blood* / Q000150:complications; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D002116:Calcitonin / Q000097:blood; D015740:Calcitonin Gene-Related Peptide; D002648:Child; D002675:Child, Preschool; D005334:Fever / Q000097:blood* / Q000209:etiology; D006801:Humans; D007223:Infant; D015850:Interleukin-6 / Q000097:blood; D007958:Leukocyte Count; D011498:Protein Precursors / Q000097:blood
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D015850:Interleukin-6; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide