MRSA colonization and infection rates among cardiovascular thoracic surgical patients

Abstract

Background: Infection due to Staphylococcus aureus is a common complication of cardiovascular and thoracic surgery (CVTS). Infections due to methicillin-resistant S aureus (MRSA), results in even greater morbidity and mortality than infections from methicillin-sensitive S aureus (MSSA) strains. To prevent such consequences, implementation of MRSA screening to identify MRSA carriers, followed by decolonization protocol is becoming a norm for cardiothoracic centres. Methods & Materials: We retrospectively studied the clinical and microbiological data of all cardiovascular thoracic surgical (CVTS) patients who were admitted for their procedure at Faculty of Medicine, University Teknologi MARA, Malaysia. The study period was five years, starting from November 2012 to October 2017. Inclusion criteria for the cases were screened for MRSA colonization upon admission, underwent appropriate decolonization procedure following detection of MRSA and remained with cardiothoracic follow-up post-surgery, for at least a month after the surgical procedure. Decolonization protocol practised by our infection control unit was the application of mupirocin ointment for nasal colonization and chlorhexidine bath for axilla and groin colonization. Results: Three hundred and fifty-eight CVTS patients were admitted for procedures during the five-year study. We identified six MRSA carriers, pre-operatively colonized at either their nose, groin or axilla. This gives an overall MRSA carrier rate of 1.7%. The majority of them, which were four patients or 67% of MRSA carriers, were colonized at their nasal sites. One patient was colonized at groin and the other one at axilla. All carriers had single-site colonization, none with multiple-sites colonization. They all successfully underwent decolonizing procedure as per protocol. Consecutively, none of the carriers developed surgical site infection (SSI) due to MRSA within a month following surgery, giving an MRSA infection rate of 0%. Conclusion: Our centre's MRSA carrier rate of less than 2% among the CVTS patients is generally lower than that reported from other similar cohorts of patients from various institutions. This, coupled with an effective decolonization protocol, appeared to have contributed to the absence of SSI due to MRSA in these patients for the past five years. The application of this ‘MRSA search and destroy’ strategy contributes not only to life-saving, but also financial saving in the long run.