C-reactive protein and the neutrophil-to-lymphocyte ratio on admission predicting bacteraemia with COVID-19

Abstract

Background

Bacteraemia can co-occur with COVID-19. The present study aimed to determine the cut-off value for C-reactive protein (CRP) and the neutrophil-to-lymphocyte ratio (NLR) for predicting bacteraemia in patients with COVID-19.

Methods

Patients admitted to Tokyo Metropolitan Tama Medical Centre for COVID-19 treatment between 1 April 2020 and 30 October 2022 were included. Patients transferred from other hospitals and those whose CRP and/or neutrophil count was not measured at admission were excluded. Community-acquired bacteraemia was diagnosed if true bacteraemia was diagnosed in patients via a blood culture performed within 72 h of admission. The cut-off value for CRP and the NLR for community-acquired bacteraemia were determined using receiver operating characteristic analysis.

Results

Among 2989 patients hospitalized for COVID-19 treatment, 19 received the diagnosis of community-acquired bacteraemia, for which CRP ≥ 6.3 was determined to be the cut-off value. The sensitivity and specificity of the cut-off was 89.5% and 73.3%, respectively. The NLR cut-off value was ≥ 7.7, which had a sensitivity and specificity of 84.2% and 84.0%, respectively.

Conclusions

Considering the possibility of the co-occurrence of bacteraemia with COVID-19, a blood culture should be performed when CRP is ≥ 6.3 or the NLR is ≥ 7.7.

Keywords:

• covid-19
• bacteraemia
• co-infection
• cRP
• nLR
• inflammation

Acknowledgements

We are indebted to the Tokyo Metropolitan Health and Hospitals Corporation and the staff at the participating branches of the Tokyo Metropolitan Hospital system for their contribution to this study.

Authors contributions

YU and NY contributed to the study design, collection, analysis, and interpretation of the data, and writing of the original draft. KM and TK contributed to the data interpretation and manuscript review and editing. All the authors approved the final version of the manuscript and confirmed that they had full access to all the data, verified the data, and accepted responsibility for the submission of this manuscript for publication.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data are stored at Tokyo Metropolitan Tama Medical Centre, and are available upon request.

Additional information

Funding

This study did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.