Risk Factors for and Clinical Outcomes of Polymicrobial Acinetobacter baumannii Bloodstream Infections.

Area of Science:

• Infectious Diseases
• Clinical Microbiology
• Bacteriology

Background:

• Acinetobacter baumannii bloodstream infections (BSI) are clinically significant.
• Polymicrobial A. baumannii BSI characteristics are underreported.
• This study investigates risk factors and outcomes of polymicrobial A. baumannii BSI.

Purpose of the Study:

• To identify risk factors associated with polymicrobial A. baumannii BSI.
• To compare clinical outcomes between polymicrobial and monomicrobial A. baumannii BSI.
• To understand the sources of polymicrobial A. baumannii BSI.

Main Methods:

• Retrospective observational study (2013-2018) in a tertiary hospital.
• Inclusion of all patients with A. baumannii BSI.
• Data collected from electronic medical records.

Main Results:

• 21% of A. baumannii BSI cases were polymicrobial.
• Common copathogens included Klebsiella pneumoniae, Pseudomonas aeruginosa, and Enterococcus faecium.
• Polymicrobial BSI more frequently originated from skin/soft tissue infections (28.6% vs. 10.5%).
• Burn injury was an independent risk factor (aOR 3.569).
• Polymicrobial BSI associated with longer hospital stay (40 vs. 27 days) and post-BSI hospitalization (22 vs. 13 days).
• No significant difference in mortality was observed.

Conclusions:

• Polymicrobial A. baumannii BSI constitutes a significant portion of cases.
• Skin and soft tissue infections are primary sources, with burn injury being a key risk factor.
• While mortality is comparable, polymicrobial BSI leads to increased healthcare utilization, warranting further investigation.