Increasing Gram-Negative Catheter-Related Bloodstream Infection in Cancer Patients

Background: We aimed to assess the incidence, etiology and outcomes of catheter-related bloodstream infection (CRBSI) in onco-hematological patients, to assess the differences between patients with hematological malignancies (HMs) and solid tumors (STs) and to identify the risk factors for Gram-negative (GN) CRBSI. Methods: All consecutive episodes of BSI in adult cancer patients were prospectively collected (2006-2020). The etiology of CRBSI was analyzed in three different 5-year periods. Risk factors for GN CRBSI were assessed in the whole cohort and separately in patients with HMs and STs. Results: Among 467 episodes of monomicrobial CRBSI, 407 were Gram-positive (GP) (87.1%), 49 GN (10.5%) and 11 fungal (2.4%). Hematological patients (369 episodes) were more frequently neutropenic and were more likely to carry central venous catheters and develop GP CRBSI. Patients with STs (98 episodes) had more comorbidities, more frequently carried port reservoirs and commonly presented more GN CRBSI. GN CRBSI significantly increased over the study period, from 5.2% to 23% (p < 0.001), whereas GP CRBSI decreased from 93.4% to 73.3% (p < 0.001). CRBSI episodes involving port reservoirs and peripherally-inserted central catheters were significantly increased (p < 0.001). The most frequent GPs were coagulase-negative staphylococci (CoNS) (57.8%) and Pseudomonas aeruginosa was the most common GN (3%). Multidrug-resistant (MDR) GN represented 32.7% of all GN CRBSIs and increased over time (p = 0.008). The independent risk factors for GN CRBSI in the whole cohort were solid tumor, chronic kidney disease and carrying a port reservoir. Carrying a port reservoir was also a risk factor in patients with STs. Health-care acquisition was identified as a risk factor for GN CRBSI in the whole cohort, as well as in patients with STs and HMs. Inadequate empirical antibiotic treatment (IEAT) occurred regardless of the etiology: 49% for GNs and 48.6% for GPs (p = 0.96). In GP CRBSI, IEAT was mainly due to inadequate coverage against CoNS (87%), whereas in GN CRBSI, IEAT was associated with multidrug resistance (54.2%). Early (48 h and 7-day) and 30-day case-fatality rates were similar when analyzed according to the type of underlying disease and etiology, except for the 30-day case-fatality rate, which was higher in the group of patients with STs compared to those with HMs (21.5% vs. 12.5%, p = 0.027). The 48 h case-fatality rate was significantly higher in patients in whom the catheter had not been removed (5.6% vs. 1%; p = 0.011), and it remained significant for GP CRBSI (6% vs. 1.3%, p = 0.023). Conclusions: GNs are an increasing cause of CRBSI in cancer patients, particularly in solid tumor patients carrying port reservoirs. Multidrug resistance among GNs is also increasing and is associated with higher rates of IEAT. Decreased 48 h survival was associated with the non-removal of the catheter. These findings should be considered when deciding on early therapeutic management for cancer patients with suspected CRBSI.