The Value of Infectious Diseases Consultation in Staphylococcus aureus Bacteremia

Background: Staphylococcus aureus bacteremia results in substantial mortality. Infectious diseases specialist consultation can improve adherence to evidence-based management of S. aureus bacteremia, but its effect on mortality is unclear. Methods: A 2-year prospective cohort study of patients with S. aureus bacteremia was performed at a large tertiary care hospital. Patients who died within 2 days of diagnosis were excluded. Independent risk factors for 28-day mortality were determined. Results: Among 341 patients with S. aureus bacteremia, 189 (55%) were male, 196 (58%) were Caucasian, 185 (54%) had methicillin-resistant S. aureus, 108 (32%) had nosocomial bacteremia, and 231 (68%) had a central venous catheter at the time of diagnosis. The median age was 56 years (range 22-95 years). A total of 111 patients (33%) had an infectious diseases consultation. Fifty-four patients (16%) died within 28 days after diagnosis. Factors associated with mortality were intensive care unit admission 48 hours or less after the first positive blood culture (adjusted hazard ratio, 4.65; 95% confidence interval [CI], 2.65-8.18), cirrhosis (adjusted hazard ratio, 4.44; 95% CI, 2.40-8.20), and advanced age (adjusted hazard ratio, 1.27 per every 10 years of age; 95% CI, 1.08-1.50). Infectious diseases consultation was associated with a 56% reduction in 28-day mortality (adjusted hazard ratio, 0.44; 95% CI, 0.22-0.89). Conclusion: Only one third of patients with S. aureus bacteremia in this cohort had an infectious diseases specialist consultation. Infectious diseases consultation was independently associated with a reduction in 28-day mortality. Routine infectious diseases consultation should be considered for patients with S. aureus bacteremia, especially those with greater severity of illness or multiple comorbidities.