Mortality, hospital length of stay, and recurrent bloodstream infections associated with extended-spectrum beta-lactamase-producing Escherichia coli in a low prevalence region: A 20-year population-based large cohort study

Abstract

ObjectivesThis population-based study aimed to investigate the risk factors and effect of extended-spectrum beta-lactamase (ESBL) production on clinical outcomes in Escherichia coli bloodstream infection (BSI) patients. MethodsThe study population was defined as patients aged ≥15 years with E. coli BSI in Queensland, Australia, from 2000 to 2019. Outcomes were defined as 30-day case fatality, hospital length of stay (LOS), and recurrent E. coli BSI. ResultsA total of 27,796 E. coli BSIs were identified, of which 1112 (4.0%) were ESBL-producers. Patients with ESBL-Ec BSI were more frequently older, male, with comorbidity, recurrent E. coli BSI, and less likely with community-associated community-onset infections as compared to non-ESBL-Ec BSI patients. The standardized mortality rate of ESBL-Ec BSI increased 8-fold from 2000 to 2019 (1 to 8 per million residents) and case fatality was 12.8% (n = 142) at 30 days from positive blood culture. Patients with ESBL-Ec BSI were not at higher risk of 30-day case fatality (adjusted hazard ratio [HR] = 0.98, 95% CI: 0.83-1.17), but had higher risk of recurring episodes (adjusted subdistribution HR = 1.58, 95% CI: 1.29-1.92) and observed 14% longer LOS (adjusted incidence rate ratio = 1.14, 95% CI: 1.10-1.18) than non-ESBL-Ec BSI patients. ConclusionIn this large patient cohort, ESBL-Ec BSI did not increase case fatality risk but observed higher hospital LOS and recurrent E. coli BSI than non-ESBL-Ec BSI. Clinical resources are warranted to account for the higher morbidity risk associated with ESBL production and incidence.