Background: Patients on total parenteral nutrition (TPN) are at risk of developing central line-associated infections. Specifically, Staphylococcus aureus bacteremia (SAB) is feared for its high complication rates. This prospective cohort study compares characteristics, clinical course and outcome of SAB in patients with and without TPN support. Methods: Clinical and microbiological data from all patients with positive blood cultures for S. aureus from two facilities, including our referral center for TPN support, were retrieved (period 2013-2020). Primary outcome was overall mortality, and included survival analysis using a multivariate Cox regression model. Secondary outcomes comprised a comparison of clinical characteristics and outcomes between both patient groups and analysis of factors associated with complicated outcome (e.g., endocarditis, deep-seated foci, relapse and death) in patients on TPN specifically. Results: A total of 620 SAB cases were analyzed, of which 53 cases received TPN at the moment the blood culture was taken. Patients in the TPN group were more frequently female, younger and had less comorbidity (p < 0.001). In-hospital death and overall mortality were significantly lower in TPN patients (4% vs. 18%, p = 0.004 and 10% vs. 34%, p < 0.001, respectively). Positive follow-up blood cultures, delayed onset of therapy and previous catheter problems were associated with a higher incidence of complicated SAB outcome in patients on TPN. Conclusion: Our data show that patients on TPN have a milder course of SAB with lower mortality rates compared to non-TPN SAB patients.
Keywords: S. aureus bacteremia; catheter-related bloodstream infection; total parenteral nutrition.