Diagnostic Accuracy of Routinely Available Biomarkers to Predict Bacteremia in Children With Community-Acquired Pneumonia: A Secondary Analysis of the GPIP/ACTIV Pneumonia Study in France, 2009–2018

Danaé Dudognon, Corinne Levy, Martin Chalumeau, Sandra Biscardi, Marie-Aliette Dommergues, François Dubos, Karine Levieux, Marie Aurel, Philippe Minodier, Ferielle Zenkhri, Ellia Mezgueldi, Irina Craiu, Laurence Morin, Stéphane Béchet, Emmanuelle Varon, Robert Cohen, Jérémie F. Cohen, The Pneumonia Study Group, François Angoulvant, Yves Gillet, Christèle Gras-Le Guen, Isabelle Hau, Laure Hees, Elise Launay, Mathie Lorrot, Fouad Madhi, Alain Martinot, Naim Ouldali

Objective(s): Blood cultures (BC), when performed in children seen in the emergency department with community-acquired pneumonia (CAP), are most of the time sterile. We described the diagnostic accuracy of white blood cells (WBC), absolute neutrophils count (ANC), C-reactive protein (CRP), and procalcitonin (PCT) to predict blood culture (BC) result in childhood CAP. Study Design: Secondary analysis of a prospective study carried out in eight pediatric emergency departments (France, 2009-2018), including children (≤15 years) with CAP. Analyses involved univariate comparisons and ROC curves. Results: We included 13,752 children with CAP. BC was positive in 137 (3.6%) of the 3,829 children (mean age 3.7 years) in whom it was performed, mostly with Streptococcus pneumoniae (n = 107). In children with bacteremia, ANC, CRP and PCT levels were higher (median 12,256 vs. 9,251/mm3, 223 vs. 72 mg/L and 8.6 vs. 1.0 ng/mL, respectively; p ≤ 0.002), but WBC levels were not. The area under the ROC curve of PCT (0.73 [95%CI 0.64-0.82]) was significantly higher (p ≤ 0.01) than that of WBC (0.51 [0.43-0.60]) and of ANC (0.55 [0.46-0.64]), but not than that of CRP (0.66 [0.56-0.76]; p = 0.21). CRP and PCT thresholds that provided a sensitivity of at least 90% were 30 mg/L and 0.25 ng/mL, respectively, for a specificity of 25.4 and 23.4%, respectively. CRP and PCT thresholds that provided a specificity of at least 90% were 300 mg/L and 20 ng/mL, respectively, for a sensitivity of 31.3 and 28.9%, respectively. Conclusions: PCT and CRP are the best routinely available predictive biomarkers of bacteremia in childhood CAP.