Microbiology of catheter-associated bloodstream infection: differences according to catheter type

Objectives: Catheter-associated bloodstream infections (CABSI) cause preventable morbidity. We compared the microbiological etiology of CABSI across different types of central and peripherally-inserted catheters. Methods: We analyzed prospectively collected CABSI data in a 2100-bed hospital network in Switzerland between 2016 and 2022. We included: short-term non-tunneled central venous catheters (CVC); long-term catheters (tunneled, or peripherally-inserted central catheters); arterial catheters; dialysis catheters; and peripheral venous catheters (PVC). We used multivariable logistic regression models to describe the risk of Staphylococcus aureus and Gram-negative pathogens according to catheter type. Results: Overall, 416 CABSI episodes were included, including 60 episodes of S. aureus and 92 episodes of Gram-negative CABSI. Microbiological profiles differed between catheter types. Together, PVC and dialysis catheters accounted for 43/60 (72%) of all S. aureus CABSI. After adjusting for age, sex, and hematology/oncology care, the odds of S. aureus were higher for hemodialysis catheters (odds ratio [OR] 17.3, 95% confidence interval [CI] 5.75-52.2, P <0.01) and PVC (OR 2.96, 95% CI 1.22-7.20, P = 0.02) compared to short-term non-tunneled CVC. Odds of Gram-negative organism as the cause of CABSI were higher in long-term catheters versus short-term non-tunneled CVC (OR 2.70, 95% CI 1.37-5.24). Conclusions: CABSI in catheters other than short-term non-tunneled CVC is more commonly caused by virulent organisms including S. aureus and Gram-negative bacteria. Catheter type should be considered when selecting empirical antimicrobial therapies.