Utility of the systemic immune-inflammation index to predict serious bacterial infections in infants with fever without a source

ABSTRACT

Introduction

This study analyzed the utility of the systemic immune-inflammation index (SII) in predicting serious bacterial infections (SBIs) in infants with fever without a source (FWS).

Methods

Infants (aged 1–4 months) evaluated in the pediatric emergency department for FWS were divided into two groups: with SBI and without SBI. The efficacy of inflammatory markers in predicting SBI was compared.

Results

The study included 223 infants with a mean age of 76.65 ± 25.42 days; 62 (27.8%) of them were included in the SBI group, and all of them were diagnosed with a urinary tract infection (UTI). The hospitalization rate and length of hospital stay were significantly higher in UTI patients (p < 0.001 for each). The mean SII was 795.76 ± 475.85 in the SBI group and 318.24 ± 300.70 in the non-SBI group, and there was a significant difference between the groups (p < 0.001). In diagnosis of SBI, the area under the curve values were found to be 0.89 [95% confidence interval (CI): 0.85–0.94] for C-reactive protein (CRP), 0.86 (95% CI: 0.81–0.91) for absolute neutrophil count (ANC), 0.84 (95% CI: 0.78–0.89) for the SII, and 0.81 (95% CI: 0.74–0.87) for WBC. In the multivariate logistic regression analysis, high CRP and SII values were found to be predictive factors for UTI without bacteremia (p < 0.001 and p = 0.008, respectively).

Conclusion

We found that high CRP and SII values could be predictive for UTI without bacteremia in infants with FWS. The SII may be preferred because it can be easily calculated using the hemogram results, is not accompanied by extra costs, and does not require further blood collection.

KEYWORDS:

• Serious bacterial infections
• infant
• fever without a source
• biomarkers

Acknowledgments

The authors gratefully acknowledge Scribendi (www.scribendi.com) for English language editing.

Author contributions

Study concept and design: Ali Güngör, Aytaç Göktuğ, Nilden Tuygun, Can Demir Karacan

Analysis and interpretation of data: Ali Güngör, Can Demir Karacan, Betül Öztürk, Razıye Merve Yaradılmış, Nilden Tuygun

Drafting of the manuscript: Ali Güngör, İlknur Bodur, Muhammed Mustafa Güneylioğlu

Critical revision of the manuscript for important intellectual content: Ali Güngör, Nilden Tuygun

Disclosure of any financial/other conflicts of interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Ethics statement

Dr. Sami Ulus Training and Research Hospital ethics committee approved the study (E-21/06-190).

Additional information

Funding

No funding was received for the production of this manuscript.