#3215 The prevalence of tunnelled line-associated MRSA and MSSA bacteraemias in a Maltese haemodialysis patient cohort between 2017 and 2024

Abstract Background and Aims Sepsis is the second most common cause of death in haemodialysis patients and patients dialysing through tunnelled dialysis lines have a 2 to 3-fold increased risk of hospitalization for infection and death compared to patients dialysing through an arteriovenous fistula or graft. This is the first audit looking at the prevalence of catheter-related blood stream infections (CRBSI) in patients receiving haemodialysis via a tunnelled line in Malta. Our aims are to benchmark local data to UK renal registry data and to assess clinical outcomes. Method CRBSI were defined as per KDOQI Vascular access 2019 definition. Data regarding demographics, tunnelled line insertion and removal dates, microbiology results and clinical outcomes (admission to intensive therapy unit, seeding and mortality) was collected retrospectively using hospital electronic records between 1st January 2017 and censored on 16th October 2024. Data was analysed using SPSS version 24.0 and Microsoft Excel. Results In total 38 episodes of CRBSI were identified during this period. Causative organisms were Methicillin sensitive Staphylococcus aureus (MSSA) in 29 cases (76.3%), Methicillin resistant Staphylococcus aureus (MRSA) in 9 cases (23.6%). Staphylococcus epidermidis was cultured concomitantly with MSSA in 1 patient and another patient with MRSA bacteraemia had concomitant growths of Finegoldia magna and Staphylococcus haemolyticus. The overall prevalence of MSSA bacteraemia during this period of time was 3.0 episodes per 100 haemodialysis patient years and for MRSA bacteraemia, 0.7 episodes per 100 haemodialysis patient years. Table 1 shows the number of CRBSI diagnosed per year, together with the rate of CRBSI per 100 haemodialysis patient years for the years where this calculation could be performed. The tunnelled line was removed in 31 cases (81.6%), salvaged in 4 (10.5%) and not documented in 3 (7.9%). The time from tunnelled line insertion to diagnosis of bacteraemia was a median of 24 days (IQR 1–1073). A total of 28 cases (73.7%) presented with early bacteraemia, diagnosed in the first 90 days after tunnelled catheter insertion. In terms of clinical outcomes and complications, 4 (10.5%) patients required Intensive care, 5 (13.1%) had confirmed infective endocarditis, and 7 (18.4%) patients died within 30 days of diagnosis of bacteraemia. Conclusion The overall prevalence of MSSA bacteraemia was higher than UK renal registry recommendations however the prevalence of MRSA bacteraemia was similar (MSSA—less than 2.5 episodes per 100 haemodialysis patient years; MRSA—less than 1.0 per 100 haemodialysis patients averaged over 2 years). During our follow-up time of almost 7 years, there was a reduction in the rate of MRSA bacteraemias however an increase in the rate of MSSA bacteraemias was noted. We plan to implement a CRBSI-prevention bundle to help reduce the prevalence of these infections further.