The good and the bad: using C reactive protein to distinguish bacterial from non-bacterial infection among febrile patients in low-resource settings

Abstract

C reactive protein (CRP), a marker for the presence of an inflammatory process, is the most extensively studied marker for distinguishing bacterial from non-bacterial infections in febrile patients. A point-of-care test for bacterial infections would be of particular use in low-resource settings where other laboratory diagnostics are not always available, antimicrobial resistance rates are high and bacterial infections such as pneumonia are a leading cause of death. This document summarises evidence on CRP testing for bacterial infections in low-income and middle-income countries (LMICs). With a push for universal health coverage and prevention of antimicrobial resistance, it is important to understand if CRP might be able to do the job. The use of CRP polarised the global health community and the aim of this document is to summarise the ‘good and the bad’ of CRP in multiple settings in LMICs. In brief, the literature that was reviewed suggests that CRP testing may be beneficial in low-resource settings to improve rational antibiotic use for febrile patients, but the positive predictive value is insufficient to allow it to be used alone as a single tool. CRP testing may be best used as part of a panel of diagnostic tests and algorithms. Further studies in low-resource settings, particularly with regard to impact on antibiotic prescribing and cost-effectiveness of CRP testing, are warranted.

COMPARISON OF sPLA2-IIA PERFORMANCE WITH HIGH-SENSITIVE CRP, NEUTROPHIL PERCENTAGE, PCT AND LACTATE TO IDENTIFY BACTERIAL INFECTION: A PROSPECTIVE STUDY

“…[22,23] Although the role of CRP was debatable as a biomarker of either inflammation or infection, [7,8] our result affirmed the stand of Escadafal et al (2020) whereby CRP levels correlated with the presence of bacterial infection and was consistent across various studies. [24] Our study showed better performance of CRP than PCT which is comparable to other LMIC context studies in contrary to the observations in high-income countries. [10,23,25] PCT played an essential role in antibiotic stewardship (AMS) and was recognised internationally for both its diagnostic and prognostic properties.…”

Tocilizumab in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

“…CRP was chosen as the biomarker for inflammation in this study since it is widely used and affordable worldwide, it is correlated with serum IL-6 concentrations, and early clinical studies of COVID-19 had reported it to be associated with severity and prognosis, with a value of greater than 50 mg/L associated with severe disease and a concentration of around 75 mg/L distinguishing fatal from non-fatal cases. 23 , 24 , 25 , 26 , 27 , 28 Whether hypoxic patients with a CRP of less than 75 mg/L could benefit from tocilizumab is unknown. There are some limitations.…”

Tocilizumab in patients admitted to hospital with COVID-19 (RECOVERY): preliminary results of a randomised, controlled, open-label, platform trial

“…CRP was chosen as the biomarker for inflammation in this study since it is widely used and affordable worldwide, it is correlated with serum IL-6 levels, and early clinical studies of COVID-19 had reported it to be associated with severity and prognosis, with a value of >50 mg/L associated with severe disease and a level of around 75 mg/L distinguishing fatal from non-fatal cases. [23][24][25][26][27][28] Whether hypoxic patients with a CRP <75 mg/L could benefit from tocilizumab is unknown. Further work is also needed to consider the health economic benefits of tocilizumab and related IL-6 inhibitors in terms of both patient outcomes and usage of healthcare resources (duration of hospital stay, and frequency of invasive mechanical ventilation and renal replacement therapy).…”