Association Between Serum C-Reactive Protein Levels and Influenza A Infection: A Cross-Sectional Study

C-reactive protein (CRP) is a nonspecific inflammatory biomarker that may be elevated during respiratory infections. However, its association with influenza A infection requires further investigation. This study aimed to assess the association between serum CRP levels and influenza A infection among patients presenting with acute respiratory symptoms. A cross-sectional study was conducted between November 2025 and February 2026 among 62 patients presenting with acute respiratory symptoms in Sabratha, Libya. Participants were classified as influenza-positive (n = 22) or influenza-negative (n = 40) according to their influenza test results. Serum CRP levels were measured using an immunoturbidimetric assay. Data were analysed using IBM SPSS Statistics, version 21.0, with statistical significance set at p < 0.05. Influenza positivity was significantly associated with cold symptoms (p = 0.001) and fatigue (p = 0.002). CRP levels were significantly higher among influenza-positive patients (p = 0.001), and a significant positive correlation was observed between CRP levels and influenza status (r = 0.664, p < 0.001). Age was not significantly associated with influenza status (p = 0.149). Elevated CRP levels were significantly associated with influenza A positivity among patients presenting with acute respiratory symptoms. CRP may serve as an adjunctive inflammatory biomarker; however, further studies are needed to establish its diagnostic accuracy and clinical utility