Mortality and length of hospital stay after bloodstream infections caused by ESBL-producing compared to non-ESBL-producing E. coli

Abstract

Objective

To compare mortality and length of hospital stay between patients with ESBL-producing E. coli bloodstream infections (BSIs) and patients with non-ESBL E. coli BSIs. We also aimed at describing risk factors for ESBL-producing E. coli BSIs and time to effective antibiotic treatment for the two groups.

Methods

A retrospective case-control study among adults admitted between 2014 and 2021 to a Norwegian University Hospital.

Results

A total of 468 E. coli BSI episodes from 441 patients were included (234 BSIs each in the ESBL- and non-ESBL group). Among the ESBL-producing E. coli BSIs, 10.9% (25/230) deaths occurred within 30 days compared to 9.0% (21/234) in the non-ESBL group. The adjusted 30-day mortality OR was 1.6 (95% CI 0.7–3.7, p = 0.248). Effective antibiotic treatment was administered within 24 hours to 55.2% (129/234) in the ESBL-group compared to 86.8% (203/234) in the non-ESBL group. Among BSIs of urinary tract origin (n = 317), the median length of hospital stay increased by two days in the ESBL group (six versus four days, p < 0.001). No significant difference in the length of hospital stay was found for other sources of infection (n = 151), with a median of seven versus six days (p = 0.550) in the ESBL- and non-ESBL groups, respectively.

Conclusion

There was no statistically significant difference in 30-day mortality in ESBL-producing E. coli compared to non-ESBL E. coli BSI, despite a delay in the administration of an effective antibiotic in the former group. ESBL-production was associated with an increased length of stay in BSIs of urinary tract origin.

Keywords:

• Extended-spectrum beta-lactamases (ESBL)
• bloodstream infection
• mortality
• Enterobacterales
• antimicrobial resistance
• healthcare associated infection

Disclosure statement

The authors report no conflict of interest.

Ethical approval

Ethical approval was granted by the Norwegian Regional Committee for Medical and Health Research Ethics (REK reference 2019/918) with a waiver of informed consent and from the Akershus University Hospital’s Data Protection Official (19/07915).

Additional information

Funding

Preliminary work received funding from the research network Turning the Tide of Antimicrobial Resistance and the Norwegian Society for Medical Microbiology. The main study received funding from Helse Sør-Øst Regional Health Authority (grant 2020012).