Diagnostic Utility of Complete Blood Count Parameters and C-Reactive Protein as Early Indicators in Febrile Children: An Outpatient Study from Tobruk, Libya

Abstract

Fever is a common presenting complaint in pediatric outpatient settings, and differentiating between viral and bacterial infections remains a clinical challenge, particularly in resource-limited regions. Simple, cost-effective biomarkers such as complete blood count (CBC) parameters and C-reactive protein (CRP) may aid in early identification of bacterial infections. The Objective of this study is to evaluate the diagnostic utility of CBC parameters (white blood cell count, neutrophil count, lymphocyte count, hemoglobin, and platelet count) and CRP as early indicators of bacterial infection in febrile children presenting to an outpatient clinic in Tobruk, Libya. A prospective cross-sectional study was conducted on 290 febrile children aged 1 month to 14 years at an outpatient pediatric clinic in Tobruk, Libya, between January and April 2026. CBC parameters and CRP levels were measured at presentation. Associations between elevated CRP and CBC parameters were assessed using the Chi-square test. Sensitivity, specificity, and predictive performance were calculated for single and combined markers. Elevated CRP was observed in 64.1% of children, leukocytosis in 62.1%, and neutrophilia in 63.8%. Significant associations were found between elevated CRP and both leukocytosis (p = 0.0003) and neutrophilia (p = 0.0001). CRP alone achieved 74.0% sensitivity and 66.0% specificity. The combination of CRP, WBC, and neutrophil counts yielded the highest diagnostic performance, with 89.0% sensitivity and 80.0% specificity. Combining CRP with WBC and neutrophil counts significantly improves diagnostic accuracy for bacterial infection in febrile children compared to any single marker. This simple, cost-effective multiparametric approach may serve as a valuable tool for risk stratification in resource-limited outpatient settings.