#4245 CATHETER-ASSOCIATED BLOODSTREAM INFECTIONS IN A HOSPITAL DIALYSIS UNIT – SEASONAL INFLUENCE AND COVID-19 PANDEMIC
Authors: Marín Irene Galindo , Mon Carmen Mon , Ortiz Milagros , Sanchez Maria , Camacho Rosa , Lentisco Carolina , Oñate Irene , Berron Juan Carlos Herrero , Oliet Aniana 
Published: June 2023

Abstract

Background and Aims
Catheter-associated bloodstream infections (CRBSI) are an important source of morbidity and mortality among patients receiving hemodialysis through a central venous catheter (CVC). Despite of the efforts to choose the arteriovenous fistula as the first vascular access, a large proportion of end stage kidney disease population initiates dialysis using these catheters. Thus, efforts to prevent catheter-associated bloodstream infections remain important. The aim of our study is to analyze the outcomes of the episodes of CRBSI in our dialysis unit. Secondly, we evaluated the seasonal distribution and the possible impact of infection-control measures implemented during COVID-19 pandemic.

Method
We conducted a single-center retrospective observational study of all cases of tunneled dialysis catheter-associated bacteremia that need hospitalization during a nine-year period (January 2013 – December 2022).

Results
A total of 67 episodes of catheter-associated bloodstream infections in 52 hemodialysis patients were registered. This translates into a total of 2 episodes per 1000 catheter-days. Among all patients, the mean age was 68.5 years, 74.6% were men and 25.4% women. Five patients (9.6%) had any type of immunosuppressive treatment. Nearly 88% used a tunneled jugular catheter as definite vascular access and the remainder used a femoral one. Eighteen of all episodes (26.9%) occurred during the first thirty days of catheter implantation. Ten of all patients (19.2%) suffer at least a second infection during the follow-up period, without differences in clinical and demographic characteristics. The microbial etiology of the infections were Gram-positive organisms in 67.2% and, within these, 83% were Staphylococcus Aureus. The catheter had to be removed in 65.7% of all cases and there were significant difference (p&lt;0.01) between Gram negative infections (preservation of 70%, successfully treated with prolonged antibiotic therapy) and Gram positive ones (preservation 12%, 3 cases of S. epidermidis and 2 cases of S. Aureus due to limited vascular tree). Admission to the intensive care unit was required in five patients and there were only two cases of endocarditis as metastasic complication. There was no death related to CRBSI. About the seasonal distribution, the majority of episodes occurs in summer and spring (43.3% and 23.9% respectively), whereas in autumn and winter there were fewer cases registered (16.4% and 16.4% in both). Despite of the increasing use of CVC as definite vascular access in our dialysis unit (almost 60%), the rate of CRBSI has been declining in parallel over the years. Since 2018, we reported less than 0.5 episodes per 1000 catheter-days.

Conclusion
This study shows a low frequency of CRBSI compared to previous studies. Among all episodes, the predominant infecting organism was methicillin-sensitive Staphylococcus Aureus (14.7% were methicillin-resistant). The early catheter removal, especially in aggressive strains as S. Aureus, reflects a low number of serious complications, with uncommon metastatic infections and no death directly related to CRBSI. A large proportion of infections were in summer; it may be attributable to hiring of less experienced professionals. We identified a substantial decline in rates of CRBSI coincident with COVID-19 pandemic. Nevertheless, this reduction was apparent beginning nearly two years before pandemic. This suggests that factors other than changes in infection-control practices during the pandemic are partially responsible of that.