Mr Matthew Richards1, Dr Caroline Marshall1
1Melbourne Health, Parkville, VIC, Australia
Introduction: In early 2017 a cluster of deep/organ space sternal surgical site infections (SSIs) following Coronary Artery Bypass Surgery (CABG) were identified. Pseudomonas aeruginosa (Pa) was isolated from the infected tissue on each occasion and subsequently a multidisciplinary incident review committee was convened to review this unusually high number of Pa infections
Method: A series of actions were undertaken that included: environmental sampling of the operating theatre, the transoesophageal echocardiogram (TOE) probe solution and post-operative ward shower heads and sinks. Molecular typing of sternal tissue isolates and environmental specimens was performed using whole genome sequencing (WGS) and multi-locus sequence typing (MLST). A review of sternal wound dressings was undertaken and a temporary change of surgical antimicrobial prophylaxis to cover Pa was implemented. Infection control practices were also reviewed.
Results: Between 1st January and March 31st 2017, four deep/organ space infections were identified with Pa isolated from the sternal tissue specimens. Three were poly-microbial and in one, only Pa was isolated. Four sternal tissue isolates were typed and were overall genetically diverse and two environmental isolates from the TOE probe solution and the ward shower head were not related to the tissue specimens.
Conclusion: A clear environmental source was not identified and there was no common strain to suggest a point source or patient-to-patient or environment-to-patient transmission. The investigation process uncovered some sub-optimal infection control processes that may have contributed. It subsequently provided an opportunity to address these significant issues and bring them in line with best practice policy.
To be advised