Persistent Staphylococcus aureus bacteremia: incidence and outcome trends over time

Area of Science:

• Infectious Diseases
• Clinical Microbiology
• Epidemiology

Background:

• Persistent Staphylococcus aureus bacteremia (SAB-P) lacks a clear definition, hindering understanding of its epidemiology and outcomes.
• Previous studies have not fully delineated the changing landscape of SAB-P.

Purpose of the Study:

• To define and assess the frequency, risk factors, and outcomes of persistent Staphylococcus aureus bacteremia (SAB-P) over time.
• To identify trends in patient characteristics and treatment associated with SAB-P.

Main Methods:

• Retrospective study of 78 patients with SAB-P using a stringent definition (bacteremia ≥ 7 days).
• Data collected from two distinct periods (2002-2003 and 2005-2006) in a single teaching hospital.
• Logistic regression analysis to identify risk factors for SAB-P.

Main Results:

• SAB-P frequency slightly increased from 11.0% to 15.1%.
• Patient characteristics evolved, with increased organ dysfunction, invasive devices, hemodialysis dependence, MRSA, and vancomycin treatment.
• Key risk factors for SAB-P included metastatic infection, vancomycin treatment, endovascular sources, and diabetes. Case-fatality rates remained stable.

Conclusions:

• The patient population with SAB is changing, with an increasing prevalence of SAB-P.
• The rise in SAB-P is likely linked to increased overall SAB, MRSA prevalence, and a growing number of high-risk patients.
• Innovative treatment strategies and risk reduction interventions are crucial for managing SAB-P.