A/Prof Leon Worth1, Dr Lyn-li Lim1, Dr Stephanie Tanamas1, Dr Ann Bull1, Dr Michael Molloy1, A/Prof. Deb Friedman1
1VICNISS, Melbourne, Australia
Biography:
A/Professor Deborah Friedman is the Director of VICNISS, coordinating and reporting HAI surveillance data for Victoria. Her research in the area of infections that develop in hospitalised patients defined the term healthcare-associated infection. She received her MD in the area of Infection Control and hospital-acquired infections and completed a Masters of Public Health. She has authored over 100 publications and is an appointed member of the Healthcare infection control special interest group (HICSIG), and an editorial board member for the American Journal of Infection Control.
Abstract:
Introduction
Since 2002, VICNISS has coordinated surgical site infection (SSI) surveillance for patients undergoing coronary artery bypass graft (CABG) surgery in Victoria. While Staphylococcus aureus continues to be responsible for the majority of SSIs, we sought to evaluate the cumulative burden of gram-negative pathogens for the period 2019-2023 and compare it with previous analyses in Victoria.
Methods
Accepted international surveillance methods (CDC/NHSN) were used by the 16 participating healthcare facilities. SSIs were classified as superficial, deep or organ-space, and pathogen data were captured for SSIs confirmed by microbiological criteria.
Results
From 2019 to 2023,13,452 CABG procedures and 299 SSI were reported (2.2% of procedures). In 107 SSIs (36%), gram-negative pathogens were isolated. Of those SSIs caused by gram-negative pathogens, 65% were superficial, 20% were deep incisional and 15% were organ space SSIs.
Overall, Pseudomonas aeruginosa and Serratia marcescens predominated, responsible for 24% and 17% of gram-negative infections respectively. Serratia spp. (including S. marcescens), have notably risen as a proportion of SSI. The most common causative organism for superficial SSI was P.aeruginosa while for deep incisional and organ space SSI, the most common causative organisms were S.marcescens, and E. coli respectively.
Conclusion
During the most recent 5 years in Victoria over one-third (and in some years over 40%) of SSI were caused by gram-negative pathogens. In particular, the rise of Serratia spp., (especially S. marcescens) should be noted in comparison with data up until a decade ago. These findings have potential implications for surgical antibiotic prophylaxis for CABG surgery.