Preoperative risk factors for postoperative Staphylococcus aureus nosocomial infections

Of the 40 million patients who undergo surgery each year in the United States, 20% may develop a postoperative nosocomial infection. Staphylococcus aureus (S. aureus) is the most common organism involved, and carriage of S. aureus in the anterior nares has been identified as a risk factor for these infections. Topical mupirocin applied to the anterior nares has been successful in eliminating S. aureus and decreasing nosocomial infections due to S. aureus. Concurrent use of preoperative chlorhexidine showers may further reduce the incidence of S. aureus surgical site infections (SSIs). In addition to treating the patient, active surveillance programs to eliminate nasal colonization in hospital surgical personnel have controlled outbreaks of S. aureus SSIs. Recently, a large study identified risk factors linked to S. aureus nasal colonization, which included obesity, male gender, and a history of a cerebrovascular accident. Protective factors included older age, current smoking, and alcohol use. Thus, by modulating these variables, investigators may create interventions aimed at reducing S. aureus nasal carriage and ultimately, postoperative nosocomial infections.