Early Bacterial Coinfections in Patients Admitted to the ICU With COVID-19 or Influenza: A Retrospective Cohort Study

Felix Bergmann; Cornelia Gabler; Alina Nussbaumer-Pröll; Michael Wölfl-Duchek; Amelie Blaschke; Christine Radtke; Markus Zeitlinger; Anselm Jorda

doi:10.1097/CCE.0000000000000895

Early Bacterial Coinfections in Patients Admitted to the ICU With COVID-19 or Influenza: A Retrospective Cohort Study

Crit Care Explor. 2023 Apr 10;5(4):e0895. doi: 10.1097/CCE.0000000000000895. eCollection 2023 Apr.

Authors

Felix Bergmann^{1

2}, Cornelia Gabler³, Alina Nussbaumer-Pröll¹, Michael Wölfl-Duchek^{1

4}, Amelie Blaschke^{1

5}, Christine Radtke², Markus Zeitlinger¹, Anselm Jorda¹

Affiliations

¹ Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
² Department of Plastic, Reconstructive and Aesthetic Surgery, Medical University of Vienna, Vienna, Austria.
³ IT Systems and Communications, Medical University of Vienna, Vienna, Austria.
⁴ Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna Austria.
⁵ Department of Infectiology and Tropical Medicine, University Clinic of Internal Medicine I, Medical University Vienna, Vienna, Austria.

Abstract

Previous findings suggest that bacterial coinfections are less common in ICU patients with COVID-19 than with influenza, but evidence is limited.

Objectives: This study aimed to compare the rate of early bacterial coinfections in ICU patients with COVID-19 or influenza.

Design setting and participants: Retrospective propensity score matched cohort study. We included patients admitted to ICUs of a single academic center with COVID-19 or influenza (January 2015 to April 2022).

Main outcomes and measures: The primary outcome was early bacterial coinfection (i.e., positive blood or respiratory culture within 2 d of ICU admission) in the propensity score matched cohort. Key secondary outcomes included frequency of early microbiological testing, antibiotic use, and 30-day all-cause mortality.

Results: Out of 289 patients with COVID-19 and 39 patients with influenza, 117 (n = 78 vs 39) were included in the matched analysis. In the matched cohort, the rate of early bacterial coinfections was similar between COVID-19 and influenza (18/78 [23%] vs 8/39 [21%]; odds ratio, 1.16; 95% CI, 0.42-3.45; p = 0.82). The frequency of early microbiological testing and antibiotic use was similar between the two groups. Within the overall COVID-19 group, early bacterial coinfections were associated with a statistically significant increase in 30-day all-cause mortality (21/68 [30.9%] vs 40/221 [18.1%]; hazard ratio, 1.84; 95% CI, 1.01-3.32).

Conclusions and relevance: Our data suggest similar rates of early bacterial coinfections in ICU patients with COVID-19 and influenza. In addition, early bacterial coinfections were significantly associated with an increased 30-day mortality in patients with COVID-19.

Keywords: COVID-19; bacterial superinfection; flu; intensive care unit; pneumonia; severe acute respiratory syndrome coronavirus 2.