Incidence, aetiology, and control of sternal surgical site infections

Since sternal surgical site infections (SSIs) can be life-threatening, every effort should be made to reduce their rate of occurrence.

To measure the rate of sternal SSIs after open heart surgery and to define the efficacy of infection control interventions in reducing this rate.

Surveillance of sternal SSIs was carried out prospectively for adult patients who underwent sternotomy between 2005 and 2012. Infection control interventions that were undertaken during the study period at different time intervals were prophylaxis with cefazolin or vancomycin, surveillance of sternal SSIs and feedback, preoperative nasal Staphylococcus aureus screening and decolonization with mupirocin, isolation of patients infected with or colonized by meticillin-resistant S. aureus, appropriate management of perioperative blood glucose level and chlorhexidine/alcohol usage for skin antisepsis.

There were 479 sternal SSIs in 18,460 patients during the study period (2.59%). The most frequent causes of sternal SSIs were coagulase-negative staphylococci (CoNS) (36%) and S. aureus (31%). Infection control interventions reduced the rate of sternal SSIs from 3.63% in 2005 to 1.65% in 2012 (P < 0.0001).

Our study shows that the rate of sternal SSIs can be decreased with proper infection control interventions. However, the interventions that were undertaken were effective only in reducing the rate of sternal SSIs caused by S. aureus. It is time to find interventions to control sternal SSIs caused by CoNS, the pathogen responsible for most sternal SSIs in hospitals where S. aureus SSIs are successfully controlled.