title: Procalcitonin and valuable clinical symptoms in the early detection of neonatal late-onset bacterial infection.
abstract: OBJECTIVE
  To evaluate which clinical symptoms indicate proven neonatal bacterial infection (NBI) and whether measuring procalcitonin aside from C-reactive protein and interleukin 6 improves sensitivity and specificity in diagnosis.
  
  
  METHODS
  In a prospective observational study, clinical symptoms and procalcitonin, C-reactive protein and interleukin 6 were simultaneously determined from the 4th day of life in 170 preterm and term neonates at the first time of suspicion of NBI. Proven NBI was defined as a positive culture of otherwise sterile body fluids or radiologically verified pneumonia in combination with elevated inflammatory markers.
  
  
  RESULTS
  Fifty-eight (34%) patients were diagnosed with proven late-onset NBI. In case of proven NBI, odds ratio and 95% confidence intervals were 2.64 (1.06-6.54) for arterial hypotension, 5.16 (2.55-10.43) for feeding intolerance and 9.18 (4.10-20.59) for prolonged capillary refill. Sensitivity of combined determination of C-reactive protein (>10 mg/L) and interleukin 6 (>100 pg/mL) was 91.4%, specificity 80.4%, positive predictive value 70.7% and negative predictive value 94.7%. The additional determination of procalcitonin (>0.7 ng/mL) resulted in 98.3%, 65.2%, 58.8% and 98.6%, respectively.
  
  
  CONCLUSIONS
  Arterial hypotension, feeding intolerance and especially prolonged capillary refill indicate proven neonatal late-onset bacterial infection, even at the time of first suspicion. Additional measurement of procalcitonin does indeed improve sensitivity to nearly 100%, but is linked to a decline in specificity. Nevertheless, in the high-risk neonatal population, additional procalcitonin measurement can be recommended because all infants with NBI have to be identified.
authors.affiliation: Department of Paediatric Pulmonology, Allergology and Neonatology, Hannover Medical School, Germany. Bohnhorst.Bettina@mh-hannover.de
authors.forename: Bettina
authors.initials: B
authors.lastname: Bohnhorst
authors.forename: Matthias
authors.initials: M
authors.lastname: Lange
authors.forename: Dorothee B
authors.initials: DB
authors.lastname: Bartels
authors.forename: Levente
authors.initials: L
authors.lastname: Bejo
authors.forename: Ludwig
authors.initials: L
authors.lastname: Hoy
authors.forename: Corinna
authors.initials: C
authors.lastname: Peter
mesh_terms: D017668:Age of Onset; D001424:Bacterial Infections / Q000175:diagnosis* / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D002196:Capillaries / Q000503:physiopathology; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D007022:Hypotension / Q000175:diagnosis / Q000453:epidemiology; D007225:Infant Food / Q000009:adverse effects; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000175:diagnosis* / Q000453:epidemiology; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D012680:Sensitivity and Specificity
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