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Original Investigation
Journal Club
January 2016

Use of Procalcitonin Assays to Predict Serious Bacterial Infection in Young Febrile Infants

Journal Club PowerPoint Slide Download
Author Affiliations
  • 1Department of Pediatrics, Antoine Béclère University Hospital, Assistance Publique-Hôpitaux de Paris, Clamart, France
  • 2INSERM, CESP Centre for Research in Epidemiology and Population Health, Paris-Sud, Paris-Saclay University, Villejuif, France
  • 3Pediatric Emergency Department, Paris Descartes University, Necker Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
  • 4Department of Pediatrics, Hôpital Mère Enfant, Nantes University Hospital, Nantes, France
  • 5Pediatric Emergency Unit and Infectious Diseases, Lille University, Lille, France
  • 6Department of Pediatrics, Poissy Hospital, Poissy, France
  • 7Department of Pediatrics, Kremlin Bicêtre University Hospital, Assistance Publique-Hôpitaux de Paris, Le Kremlin-Bicêtre, France
  • 8Department of Pediatrics, Dupuytren University Hospital, Limoges, France
  • 9Department of Pediatrics, Jean Verdier Hospital, Assistance Publique-Hôpitaux de Paris, Paris 13 University, Bondy, France
  • 10Department of Pediatrics, Sud Francilien Hospital, Corbeil-Essonnes, France
  • 11Department of Pediatrics, Centre Hospitalier de Marne La Vallée, Jossigny, France
  • 12Department of Pediatrics, Créteil Hospital, Créteil, France
  • 13Department of Paediatric Surgery, Hôpital d'Enfants de La Timone, Marseille, France
  • 14Department of Pediatrics, Rouen University Hospital, Rouen, France
  • 15Department of Pediatrics, Louis Mourier University Hospital, Assistance Publique-Hôpitaux de Paris, Colombes, France
  • 16Pediatric Emergency Unit, Hôpitaux Pédiatriques de Nice, CHU Lenval, Nice, France
  • 17Assistance Publique-Hôpitaux de Paris, Hôpital Paul Brousse, Virologie, National Reference Laboratory for Maternofetal Rubella Infections, Villejuif, France
JAMA Pediatr. 2016;170(1):62-69. doi:10.1001/jamapediatrics.2015.3210

Importance  The procalcitonin (PCT) assay is an accurate screening test for identifying invasive bacterial infection (IBI); however, data on the PCT assay in very young infants are insufficient.

Objective  To assess the diagnostic characteristics of the PCT assay for detecting serious bacterial infection (SBI) and IBI in febrile infants aged 7 to 91 days.

Design, Setting, and Participants  A prospective cohort study that included infants aged 7 to 91 days admitted for fever to 15 French pediatric emergency departments was conducted for a period of 30 months (October 1, 2008, through March 31, 2011). The data management and analysis were performed from October 1, 2011, through October 31, 2014.

Main Outcomes and Measures  The diagnostic characteristics of the PCT assay, C-reactive protein (CRP) concentration, white blood cell (WBC) count, and absolute neutrophil cell (ANC) count for detecting SBI and IBI were described and compared for the overall population and subgroups of infants according to the age and the duration of fever. Laboratory test cutoff values were calculated based on receiver operating characteristic (ROC) curve analysis. The SBIs were defined as a pathogenic bacteria in positive culture of blood, cerebrospinal fluid, urine, or stool samples, including bacteremia and bacterial meningitis classified as IBIs.

Results  Among the 2047 infants included, 139 (6.8%) were diagnosed as having an SBI and 21 (1.0%) as having an IBI (11.0% and 1.7% of those with blood culture (n = 1258), respectively). The PCT assay offered an area under the curve (AUC) of ROC curve similar to that for CRP concentration for the detection of SBI (AUC, 0.81; 95% CI, 0.75-0.86; vs AUC, 0.80; 95% CI, 0.75-0.85; P = .70). The AUC ROC curve for the detection of IBI for the PCT assay was significantly higher than that for the CRP concentration (AUC, 0.91; 95% CI, 0.83-0.99; vs AUC, 0.77; 95% CI, 0.65-0.89; P = .002). Using a cutoff value of 0.3 ng/mL for PCT and 20 mg/L for CRP, negative likelihood ratios were 0.3 (95% CI, 0.2-0.5) for identifying SBI and 0.1 (95% CI, 0.03-0.4) and 0.3 (95% CI, 0.2-0.7) for identifying IBI, respectively. Similar results were obtained for the subgroup of infants younger than 1 month and for those with fever lasting less than 6 hours.

Conclusions and Relevance  The PCT assay has better diagnostic accuracy than CRP measurement for detecting IBI; the 2 tests perform similarly for identifying SBI in febrile infants aged 7 to 91 days.