An Increase in SSI Rate Complicating Coronary Artery Bypass Graft (CABG) surgery following a Change from Chlorhexidine to Triclocarban Antiseptic

Background: Barwon Health in Victoria, Australia performs approximately 340 CABG cases per year. The mean deep/organ space sternal SSI rate from 2002-2008 was 1.6% (range 0.6-2.4%).

Objective: To describe an increase in SSI rate starting in mid-2008, following a change in preoperative scrub from Chlorhexidine gluconate to SapodermŽ soap.

Methods: In 2009, an increase in the SSI rate post CABG was detected and an investigation was undertaken. Available bacterial isolates were stored and ribotyping was undertaken.

Results: The SSI rate for 2009 increased and included 8 deep or organ space sternal SSI of 266 procedures (3%). The majority of SSI were caused by Staphylococcus aureus. In July of 2008 preoperative scrub was switched from Chlorhexidine gluconate to SapodermŽ soap due to the decreased price of the latter product. Sapoderm was previously produced containing triclosan, however, in 2009 its active ingredient was switched to triclocarban. Following the change in antiseptic shower regimen in mid-2008, 12 deep or organ space sternal SSI were detected over 13 months, compared with only 5 such SSI in the previous 12 month period. The proportion of sternal or donor site SSI caused by S. aureus also increased. From 21% of SSI (4/19) in 2007,10% of SSI (2/20) in 2008, to 61% of SSI (11/18) in 2009. Molecular typing of MSSA isolates revealed that two-thirds were identical. Unfortunately susceptibility testing against TCC was not available in our state. Triclocarban (TCC) is a substance with anti-bacterial properties that is used in disinfectants and soaps and other household products. Daily bathing with TCC has been shown to reduce Staphylococcus aureus skin colonization. However, TCC is only bacteriostatic against S. aureus, and S. aureus strains with low-level resistance to triclosan have emerged. Preoperative showering and scrubbing with 4% chlorhexidine gluconate has been found to be more effective than triclocarban medicated soap in reducing skin colonization at the site of surgical incision.

Conclusions: Although causation cannot be proven in this case, we hypothesize that a change in antiseptic shower preparation preoperatively contributed to an increase in SSI rate, and an increased proportion of SSIs caused by S.aureus