Risk factors for Staphylococcus aureus colonization in a presurgical orthopedic population

Preoperative colonization with Staphylococcus aureus (SA) increases risk of surgical site infection. Screening for SA followed by skin and nasal decolonization can help to reduce the risk of postoperative infections. Risk factors for colonization are, however, not completely understood.

A case-control study using questionnaires and patient demographics specifically designed to observe SA colonization risk factors in a presurgical orthopedic population. A total of 115 subjects with a positive preoperative screen for SA nasal colonization prior to orthopedic surgery completed a questionnaire to assess for SA risk factors: these subjects served as our cases. An additional 476 controls completed similar questionnaires. Data collected included demographic, health, and lifestyle information. Multivariable logistic regression was used to generate odds ratios (OR) for risk of SA colonization.

Several risk factors were identified. Male sex (OR 2.3; 95% confidence interval [CI], [1.4-3.8]) and diabetes (OR 3.8 [1.8-7.8]) significantly increased the risk of SA colonization. Older age, visiting public places (OR 0.2 [0.1-0.3]), recent antibiotic use (OR 0.2 [0.1-0.6]), and the presence of facial hair (OR 0.3 [0.1-0.6]) significantly lowered the risk of SA colonization.

By identifying patients who may be at greater risk of SA colonization, we can better streamline our presurgical techniques to help reduce risk of surgical site infections and improve patient outcomes.