The value of C-reactive protein as a marker of bacterial infection in patients with septicaemia/endocarditis and influenza

Scand J Infect Dis. 1989;21(5):543-9. doi: 10.3109/00365548909037883.


In order to evaluate the capacity of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), white blood cell count (WBC) and polymorphonuclear neutrophils (PMNs) to differentiate between bacterial and viral infection we studied 176 patients with septicaemia/endocarditis (SE), 59 patients with uncomplicated influenza (UI) and 22 patients with complicated influenza (CI) retrospectively. All 4 parameters were significantly more elevated in SE and CI than in UI. Among patients with SE 10 176 had a CRP value less than 50 mg/l and in patients with UI 5/56 had a CRP value greater than 100 mg/l. Patients with SE caused by pneumococci had the highest CRP levels and patients with alfa-haemolytic streptococci the lowest. The sensitivity and specificity favours the use of CRP as an indicator of bacterial superinfection in influenza.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers / blood
  • Blood Sedimentation
  • C-Reactive Protein / analysis*
  • Child
  • Endocarditis, Bacterial / blood*
  • Endocarditis, Bacterial / complications
  • Female
  • Humans
  • Influenza, Human / blood*
  • Influenza, Human / complications
  • Leukocyte Count
  • Male
  • Middle Aged
  • Neutrophils
  • Retrospective Studies
  • Sepsis / blood*
  • Sepsis / complications
  • Superinfection / blood*
  • Superinfection / complications


  • Biomarkers
  • C-Reactive Protein