Using the kinetics of C-reactive protein response to improve the differential diagnosis between acute bacterial and viral infections

Infection. 2020 Apr;48(2):241-248. doi: 10.1007/s15010-019-01383-6. Epub 2019 Dec 24.

Abstract

Purpose: Differential diagnosis between acute viral and bacterial infection is an emerging common challenge for a physician in the emergency department. Serum C-reactive protein (CRP) is used to support diagnosis of bacterial infection, but in patients admitted with low CRP, its ability to discriminate between viral and bacterial infections is limited. We aimed to use two consecutive CRP measurements in order to improve differential diagnosis between bacterial and viral infection.

Methods: A single-center retrospective cohort (n = 1629) study of adult patients admitted to the emergency department with a subsequent microbiological confirmation of either viral or bacterial infection. Trend of CRP was defined as the absolute difference between the first two measurements of CRP divided by the time between them, and we investigated the ability of this parameter to differentiate between viral and bacterial infection.

Results: In patients with relatively low initial CRP concentration (< 60 mg/L, n = 634 patients), where the uncertainty regarding the type of infection is the highest, the trend improved diagnosis accuracy (AUC 0.83 compared to 0.57 for the first CRP measurement). Trend values above 3.47 mg/L/h discriminated bacterial from viral infection with 93.8% specificity and 50% sensitivity.

Conclusions: The proposed approach for using the kinetics of CRP in patients whose first CRP measurement is low can assist in differential diagnosis between acute bacterial and viral infection.

Keywords: Bacterial; C-reactive protein; Differential diagnosis; Infection; Viral.

MeSH terms

  • Acute Disease
  • Adaptor Proteins, Signal Transducing / blood
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Adult
  • Aged
  • Aged, 80 and over
  • Area Under Curve
  • Bacterial Infections / blood
  • Bacterial Infections / diagnosis*
  • Carrier Proteins / blood
  • Carrier Proteins / metabolism*
  • Cohort Studies
  • Diagnosis, Differential
  • Female
  • Humans
  • LIM Domain Proteins / blood
  • LIM Domain Proteins / metabolism*
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Retrospective Studies
  • Sensitivity and Specificity
  • Virus Diseases / blood
  • Virus Diseases / diagnosis*

Substances

  • Adaptor Proteins, Signal Transducing
  • CRIP1 protein, human
  • CRIP2 protein, human
  • Carrier Proteins
  • LIM Domain Proteins