Objectives: Catheter-associated bloodstream infections (CABSI) cause preventable morbidity. We compared the microbiological aetiology of CABSI across different types of central and peripherally inserted catheters.

Methods: We analysed prospectively collected CABSI data in a 2100-bed hospital network in Switzerland between 2016 and 2022. We included: short-term non-tunnelled central venous catheters (CVC); long-term catheters (tunnelled, or peripherally inserted central catheters); arterial catheters; dialysis catheters; and peripheral venous catheters (PVC). We used multivariable logistic regression models to describe risk of Staphylococcus aureus and Gram-negative pathogens according to catheter type.

Results: 416 CABSI episodes were included, including 60 episodes of S. aureus and 92 episodes of Gram-negative CABSI. Microbiological profile 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 haematology/oncology care, odds of S. aureus were higher for haemodialysis catheters (OR 17.3, 95% 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-tunnelled CVC. Odds of Gram-negative organism as cause of CABSI were higher in long-term catheters versus short-term non-tunnelled CVC (OR 2.70, 95% CI 1.37-5.24).

Conclusions: CABSI in catheters other than short-term non-tunnelled CVC are more commonly caused by virulent organisms including S. aureus and Gram-negative bacteria. Catheter type should be considered when selecting empirical antimicrobial therapies.