C-reactive protein as a diagnostic marker of bacterial infection in febrile children

Introduction: Evaluation of febrile infants and children without focus possess a great clinical concern. Although several biochemical indices indicate diagnosis towards bacterial agents, combining low cost and easily performed haematological parameters could reasonably predict the presence of Bacterial Infection (BI). Aim: To assess the value of C-reactive Protein (CRP) alone and in conjunction with total White Blood Cell (WBC) count and Absolute Neutrophil Count (ANC) in predicting bacterial infection in febrile children. Materials and Methods: A prospective study was conducted in the Department of Paediatrics of a tertiary care hospital among children aged 1 month to 14 years admitted with fever for >24 hours. Data were collected from 97 consecutive children in whom CRP and total blood count was advised at admission. These data were analysed to predict the presence of BI by investigating the diagnostic performance of CRP, WBC and ANC using standard statistical software Stata version 13.1. Results: BI was diagnosed in 41 children. Sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV), Diagnostic Accuracy (DA) of CRP for BI among the febrile infants were 83%, 75.0%, 71%, 86% and 78% respectively. The sensitivity and specificity were 61% and 98% when all the three parameters CRP, WBC and ANC were positive and were 95% and 45% when any of these parameters was positive. Conclusion: A definitive cut-off value of 1.2 mg/L for CRP is a reasonably good predictor of BI among febrile children. However, addition of other laboratory parameters (total leukocyte count and ANC may enhance clinicians’ ability to discriminate bacterial from non BIs.