A 5-Year Population-Based Study of Polymicrobial Enterococcal Bloodstream Infection in Southeast Minnesota

Area of Science:

• Infectious Diseases
• Epidemiology
• Clinical Microbiology

Background:

• Polymicrobial enterococcal bloodstream infections (PE-BSI) represent a significant clinical challenge.
• Understanding the epidemiology and outcomes of PE-BSI is crucial for public health.
• Enterococcal infections can lead to severe complications and increased mortality.

Purpose of the Study:

• To determine the incidence and epidemiology of PE-BSI in a defined US population.
• To investigate the clinical outcomes, including mortality, associated with PE-BSI.
• To identify risk factors and common sources of PE-BSI.

Main Methods:

• A population-based study was conducted in 8 counties in southeast Minnesota.
• Incident PE-BSI cases in adults (≥18 years) from 2018-2022 were identified using the Expanded Rochester Epidemiology Project (E-REP).
• Incidence rates were calculated per 100,000 person-years; multivariable analysis identified associated factors.

Main Results:

• The age- and sex-adjusted incidence rate of PE-BSI was 4.1 cases per 100,000 person-years.
• Older age and male sex were significantly associated with increased PE-BSI incidence (P<.001).
• The most common source was non-urinary intra-abdominal (40.9%), with Enterococcus faecalis being the predominant isolate (69.7%).
• Mortality rates were high at 31.8% at 12 weeks and 47.3% at 1 year, despite low rates of endocarditis and relapse.

Conclusions:

• Increased PE-BSI incidence is linked to older age and male sex in this population.
• Non-urinary intra-abdominal infections are a frequent source of PE-BSI.
• PE-BSI is associated with substantial cumulative mortality.