Single Centre Study Identifying the Impact of COVID-19 on Patterns of Bacteremia in Patients on Haemodialysis

Background: Haemodialysis (HD) patients have an increased risk of death due to bacteraemia; with central venous catheters for dialysis, being a key risk factor. The coronavirus-19 (COVID -19) pandemic further accelerated mortality and morbidity rates in these patients, partly due to co-morbidities and regular hospital visits for dialysis. We analysed the prevalence of bacteraemias in HD patients between 2019-2024, specifically assessing type and source of organism, and antibiotic resistance. Methods: HD patients with a bacteraemia between 2019-2024 were identified from the Microbiology and Renal databases. Data included causative organism, antibiotic sensitivity, type of HD access, source of bacteraemia and patient outcome. Contaminants and repeat positive cultures within the space of one week which grew the same organism were excluded from the analyses. Results: Prevalence of organisms 423 bacteraemias were recorded, of which 177 were not repeats, or contaminants. 74% were line associated, 2% were from AV fistulae, the rest were from other sources e.g osteomyelitis. 72.8% were Gram positive, 24.2% were Gram negative and 0.2% were fungi. There was an increased number of bacteraemias in 2020 and 2021, and the prevalence of Enterococci was greatest in 2020. Of the Gram positives, 40.6% were coagulase positive, 43.7% were coagulase negative, and 9.3% were enterococci. In Gram positive organisms, apart from one case of Microbacterium sp., Vancomycin resistance was only seen with enterococci, of which 58% were Vancomycin resistant. Conclusion: We found an increase in bacteraemias in 2020-2021. It coincided with the start of the pandemic. It is not clear whether/if this was related to COVID-19, but it is interesting to see that it settled over the next two years back towards ‘baseline’. This would have been around the time that COVID vaccination was being rolled out, and the dialysis patients, in view of being in the vulnerable group, were given priority for this. Vancomycin is the empirical antibiotic of choice for Gram positive organisms in our unit and 91% of Gram positive isolates were Vancomycin sensitive. The ‘spike’ in VREs in 2020 highlights the importance of anti-microbial stewardship and continued surveillance to detect development of resistance in order to adjust anti-microbial guidelines if needed.